##### Quantum Information Processing

- Multi-parameter quantum magnetometry with spin states in coarsened measurement reference (2019/06/17 02:00)
### Abstract

We investigate the simultaneous estimation of the intensity and the orientation of a magnetic field by the multi-parameter quantum Fisher information matrix. A general expression is achieved for the simultaneous estimation precision of the intensity and the orientation, which is better than the independent estimation precision for the given number of spin states. Moreover, we consider an imperfect measurement device, coarsened measurement reference. For the case of the measurement reference rotating around the

*y*-axis randomly, the simultaneous estimation always performs better than the independent estimation. For all other cases, the simultaneous estimation precision will not perform better than the independent estimation when the coarsened degree is larger than a certain value. - Practical quantum private query of blocks based on the two-dimensional QKD system (2019/06/15 02:00)
### Abstract

Quantum private query of blocks (QPQB) allow user to obtain meaningful multiple consecutive bits in one query, which has certain advantages in improving communication efficiency and protecting user privacy. However, previous QPQB protocols generally show poor practicability for the use of high-dimensional quantum system (which is difficult to implement) or the ignorance of error correction (as a result, user may pay for a false database item). To solve this problem, we proposed a new fault-tolerant quantum protocol for private query of blocks based on the two-dimensional quantum system, by using a special reorder-shift-addition technique. This technology can not only compress user’s additional information obtained in error correction, but also can reduce the user’s advantage obtained from the alignment of the key bits in bitwise adding, solving an inherent security problem in postprocessing. Moreover, our protocol is loss tolerant and can resist the quantum memory attack.

- CHSH inequalities with appropriate response function for POVM and their quantum violation (2019/06/13 02:00)
### Abstract

In the derivation of local bound of a Bell’s inequality, the response functions corresponding to the different outcomes of measurements are fixed by the relevant hidden variables irrespective of the fact whether the measurement is unsharp. In the context of a recent result by Spekkens that tells even in a ontological theory the unsharp observable cannot be assigned a deterministic response function, we derive a modified local bound of CHSH inequality in unsharp measurement scenario. We consider response function for a given POVM which is determined by the response functions of the relevant projectors appearing in its spectral representation. In this scenario, the local bound of CHSH inequality is found to be dependent on the unsharpness parameter. This then enables us to show that the quantum violation of CHSH inequality for unbiased spin-POVMs occurs whenever there is violation for their sharp counterpart. For the case of biased POVMs, it is shown that the quantum violation of CHSH inequality can be obtained for ranges of sharpness parameter for which no violation obtained using standard local bound of CHSH inequality.

- Growth rate of quantum knot mosaics (2019/06/12 02:00)
### Abstract

Since the Jones polynomial was discovered, the connection between knot theory and quantum physics has been of great interest. Knot mosaic theory was introduced by Lomonaco and Kauffman in the paper ‘Quantum knots and mosaics’ to give a precise and workable definition of quantum knots, intended to represent an actual physical quantum system. This paper is inspired by an open question about the knot mosaic enumeration suggested by them. A knot (

*m*,*n*)-mosaic is an \(m \times n\) array of 11 mosaic tiles representing a knot or a link diagram by adjoining properly. The total number \(D_{m,n}\) of knot (*m*,*n*)-mosaics, which indicates the dimension of the Hilbert space of the quantum knot system, is known to grow in a quadratic exponential rate. Recently, the first author showed the existence of the knot mosaic constant \(\delta = \lim _{m, n \rightarrow \infty } (D_{m,n})^{\frac{1}{mn}}\) and proved \(4 \le \delta \le \frac{5+ \sqrt{13}}{2} = 4.302\cdots \) by developing an algorithm producing the exact enumeration of knot mosaics, which uses a recursion formula of state matrices. In this paper, we give a simpler proof of the lower bound and improve the upper bound of the knot mosaic constant as $$\begin{aligned} 4 \le \delta \le 4.113\cdots \end{aligned}$$ by introducing two new concepts: quasimosaics and cling mosaics. - Deterministic joint remote preparation of arbitrary multi-qubit states via three-qubit entangled states (2019/06/11 02:00)
### Abstract

We propose an efficient scheme for joint remote state preparation (JRSP) of arbitrary multi-qubit states from two senders to one receiver with the 100% successful probability. Quantum channel is composed of maximally three-qubit entangled states, and several special mutually orthogonal measurement basis are constructed without the introduction of auxiliary particles. We also calculate the total classical communication cost required in the JRSP processes. The concrete JRSP procedures for remotely preparing single-qubit and two-qubit states are illustrated to prove explicitly the feasibility of this JRSP protocol.

- Estimation of entanglement in bipartite systems directly from tomograms (2019/06/11 02:00)
### Abstract

We investigate the advantages of extracting the degree of entanglement in bipartite systems directly from tomograms, as it is the latter that are readily obtained from experiments. This would provide a superior alternative to the standard procedure of assessing the extent of entanglement between subsystems after employing the machinery of state reconstruction from the tomogram. The latter is both cumbersome and involves statistical methods, while a direct inference about entanglement from the tomogram circumvents these limitations. In an earlier paper, we had identified a procedure to obtain a bipartite entanglement indicator directly from tomograms. To assess the efficacy of this indicator, we now carry out a detailed investigation using two nonlinear bipartite models by comparing this tomographic indicator with standard markers of entanglement such as the subsystem linear entropy and the subsystem von Neumann entropy and also with a commonly used indicator obtained from inverse participation ratios. The two-model systems selected for this purpose are a multilevel atom interacting with a radiation field, and a double-well Bose–Einstein condensate. The role played by the specific initial states of these two systems in the performance of the tomographic indicator is also examined. Further, the efficiency of the tomographic entanglement indicator during the dynamical evolution of the system is assessed from a time-series analysis of the difference between this indicator and the subsystem von Neumann entropy.

- CNOT gate on reverse photon modes in a ring cavity (2019/06/08 02:00)
### Abstract

Photon modes of the reverse rotation in a ring QED cavity coupled with a single atom are considered. By applying the Schrieffer–Wolf transformation for the off-resonant light–atom interaction, an effective Hamiltonian of the photon modes evolution is obtained. Heisenberg equations for the input–output photon mode operators are written, and the expression for the wave function of the system is found. The analytical solution shows the condition of the control NOT quantum gate implementation on chiral photon modes. A possible on-chip experimental implementation and recommendations for the construction of an optical quantum computer using this gate are considered.

- Interaction of light and semiconductor can generate quantum states required for solid-state quantum computing: entangled, steered and other nonclassical states (2019/06/07 02:00)
### Abstract

Proposals for solid-state quantum computing are extremely promising as they can be used to build room temperature quantum computers. If such a quantum computer is ever built, it would require built-in sources of nonclassical states required for various quantum information processing tasks. Possibilities of generation of such nonclassical states are investigated here for a physical system composed of a monochromatic light coupled to a two-band semiconductor with direct band gap. The model Hamiltonian includes both photon–exciton and exciton–exciton interactions. Time evolution of the relevant bosonic operators is obtained analytically by using a perturbative technique that provides operator solution for the coupled Heisenberg’s equations of motion corresponding to the system Hamiltonian. The bosonic operators are subsequently used to study the possibilities of observing single- and two-mode squeezing and antibunching after interaction in the relevant modes of light and semiconductor. Further, entanglement between the exciton and photon modes is reported. Finally, the nonclassical effects have been studied numerically for the open quantum system scenario. In this situation, the nonlocal correlations between two modes are shown to violate EPR steering inequality. The observed nonclassical features, induced due to exciton–exciton pair interaction, can be controlled by the phase of input field, and the correlations between two modes are shown to enhance due to nonclassicality in the input field.

- A Poisson Model for Entanglement Optimization in the Quantum Internet (2019/06/05 02:00)
### Abstract

We define a nature-inspired model for entanglement optimization in the quantum Internet. The optimization model aims to maximize the entanglement fidelity and relative entropy of entanglement for the entangled connections of the entangled network structure of the quantum Internet. The cost functions are subject of a minimization defined to cover and integrate the physical attributes of entanglement transmission, purification, and storage of entanglement in quantum memories. The method can be implemented with low complexity that allows a straightforward application in the quantum Internet and quantum networking scenarios.

- High-throughput and low-cost LDPC reconciliation for quantum key distribution (2019/06/04 02:00)
### Abstract

Reconciliation is a crucial procedure in post-processing of quantum key distribution (QKD), which is used for correcting the error bits in sifted key strings. Although most studies about reconciliation of QKD focus on how to improve the efficiency, throughput optimizations have become the highlight in high-speed QKD systems. Many researchers adopt high-cost GPU implementations to improve the throughput. In this paper, an alternative high-throughput and high-efficiency solution implemented in low-cost CPU is proposed. The main contribution of the research is the design of a quantized LDPC decoder including improved RCBP-based check node processing and saturation-oriented variable node processing. Experiment results show that the throughput up to 60 Mbps is achieved using the bidirectional approach with reconciliation efficiency approaching to 1.1, which is the optimal combination of throughput and efficiency in discrete-variable QKD. Meanwhile, the performance remains stable when quantum bit error rate varies from 1 to 8%.

- Entanglement-breaking of quantum dynamical channels (2019/06/04 02:00)
### Abstract

Entanglement is a key issue in the quantum physics which gives rise to resources for achieving tasks that are not possible within the realm of classical physics. Quantum entanglement varies with the evolution of the quantum systems. It is of significance to investigate the entanglement dynamics in terms of quantum channels. We study the entanglement-breaking channels and present the necessary and sufficient conditions for a quantum channel to an entanglement-breaking one for qubit systems. Furthermore, a concept of strong entanglement-breaking channel is introduced. The amendment of entanglement-breaking channels is also studied.

- Variational learning the SDC quantum protocol with gradient-based optimization (2019/06/03 02:00)
### Abstract

Recently, a variational learning approach is adopted to discover quantum communication protocols (Wan et al. in npj Quantum Inf 3:36, 2017). Because designing quantum protocols manually is a delicate and difficult work, this variational learning approach is well worth further study. In this paper, we use the same approach to learn the simultaneous dense coding (SDC) protocols with two or three receivers. The gradient-based optimization is used to learn the parameters of the locking operator of the SDC protocol. Two different designs of the loss function are considered. Numerical experiment results show the effectiveness of this variational learning approach.

- Security loopholes in the controlled quantum dialogue robust against conspiring users protocol (2019/06/01 02:00)
### Abstract

Recently, a new controlled quantum dialogue (CQD) protocol which is secure against the conspiring attack from the users without the controller’s permission was put forward. However, it is found that this CQD protocol is weak against the different initial state (DIS) attack and the denial-of-service (DoS) attack from the dishonest controller. For the DIS attack, the controller prepares different initial states to eavesdrop on the users’ messages. For the DoS attack, the controller deliberately announces the wrong classical information which is used for the users to encode secret messages, and thus, one user gets the wrong message from the other user. To mend the DIS attack, a security check to the controller is added to prevent the dishonest controller from preparing the different initial states. To mend the DoS attack, a message authentication is added to prevent the dishonest controller from publishing the wrong classical information. It shows that the security check to the controller and the message authentication can effectively prevent the DIS attack and the DoS attack from the dishonest controller, respectively.

- Novel multi-bit quantum comparators and their application in image binarization (2019/06/01 02:00)
### Abstract

Quantum image processing has attracted much attention since it offers a potential solution to efficiently calculate some hard problems much faster than classical image processing. In particular, it is a basic operation to change each image pixel into black or white, named as a binary image. Here we present novel multi-bit quantum comparators to realize quantum image binarization. These comparators compare two quantum logic states and identify which of them is the largest. We analyze the superior performance of our proposed comparators in terms of quantum cost, quantum delay and auxiliary bits compared with the existing comparators. Furthermore, our quantum image binarization exploits the advantages of our proposed multi-bit comparators to change the values of image pixels into 0 or 255.

- Nonlinear dynamics of a quantum Cournot duopoly game with heterogeneous players (2019/05/31 02:00)
### Abstract

In this paper, a dynamic quantum Cournot duopoly game with heterogeneous players is proposed by applying the Li–Du–Massar scheme. We analyze the influence of the degree of quantum entanglement (DQE) on stability and dynamics behavior of the system. The result shows that: (i) The corresponding classical Cournot duopoly game is a special case of the dynamic quantum Cournot duopoly game. (ii) The stability region may increase or decrease as the DQE increases. It depends on the relative marginal cost difference. (iii) Numerical simulations show that the complicated dynamics behaviors of quantum Cournot game is different from that of corresponding classical model.

- A layered quantum communication path protocol cross multiple participants based on entanglement swapping (2019/05/30 02:00)
### Abstract

Quantum entanglement provides a contemporary secure channel for information communication, and the entanglement swapping builds newly entanglement on the previous isolate particles without direct interaction. In the paper, a novel-layered quantum communication path protocol cross multiple participants based on entanglement swapping is proposed, in which the communication path from sender to receiver across multiple intermediate nodes is constructed, and the constructed quantum channel is served for the information exchange. The present protocol can transmit message from sender to receiver via entanglement swapping. The presented protocol is useful for long-distance quantum information communication, significant to quantum network design and plan.

- Quantum circuit design for objective function maximization in gate-model quantum computers (2019/05/30 02:00)
### Abstract

Gate-model quantum computers provide an experimentally implementable architecture for near-term quantum computations. To design a reduced quantum circuit that can simulate a high-complexity reference quantum circuit, an optimization should be taken on the number of input quantum states, on the unitary operations of the quantum circuit, and on the number of output measurement rounds. Besides the optimization of the physical layout of the hardware layer, the quantum computer should also solve difficult computational problems very efficiently. To yield a desired output system, a particular objective function associated with the computational problem fed into the quantum computer should be maximized. The reduced gate structure should be able to produce the maximized value of the objective function. These parallel requirements must be satisfied simultaneously, which makes the optimization difficult. Here, we demonstrate a method for designing quantum circuits for gate-model quantum computers and define the Quantum Triple Annealing Minimization (QTAM) algorithm. The aim of QTAM is to determine an optimal reduced topology for the quantum circuits in the hardware layer at the maximization of the objective function of an arbitrary computational problem.

- Quantum trajectories for environment in superposition of coherent states (2019/05/29 02:00)
### Abstract

We derive stochastic master equations for a quantum system interacting with a Bose field prepared in a superposition of continuous-mode coherent states. To determine a conditional evolution of the quantum system, we use a collision model with an environment given as an infinite chain of not interacting between themselves qubits prepared initially in an entangled state being a discrete analogue of a superposition of coherent states of the Bose field. The elements of the environment chain interact with the quantum system in turn one by one, and they are subsequently measured. We determine a conditional evolution of the quantum system for continuous in time observations of the output field as a limit of discrete recurrence equations. We consider the stochastic master equations for a counting as well as for a diffusive stochastic process.

- Characterizing nonclassical correlation using affinity (2019/05/28 02:00)
### Abstract

Geometric discord (GD), a measure of quantumness of bipartite system, captures minimal nonlocal effects of a quantum state due to locally invariant von Neumann projective measurements. The original version of GD is suffered by local ancilla problem. In this article, we propose a new version of geometric discord using affinity. This quantity satisfies all the necessary criteria of a good measure of quantum correlation for bipartite system and resolves local ancilla problem. We evaluate analytically the proposed discord for both pure and mixed states. For an arbitrary pure state, it is shown that affinity-based geometric discord is same as geometric measure of entanglement. Further, a lower bound of this measure for \(m \times n\) -dimensional arbitrary mixed state and a closed formula of proposed version of geometric discord for \(2 \times n\) -dimensional mixed state are obtained. Finally, as are illustrations, we have studied the quantum correlation of Bell diagonal state, isotropic and Werner states.

- Quantum robots can fly; play games: an IBM quantum experience (2019/05/27 02:00)
### Abstract

Quantum robot is an excellent future application that can be achieved with the help of a quantum computer. As a practical example, quantum-controlled Braitenberg vehicles proposed by Raghuvanshi et al. (in: Proceedings of the 37th international symposium on multiple-valued logic, 2007) is a mobile quantum system and hence acts as a quantum robot. Braitenberg vehicles are simple circuit robots which can experience natural behaviours like fear, aggression and love. These robots can be controlled by quantum circuits incorporating quantum principles such as entanglement and superposition. Complex behaviours can be mimicked by a quantum circuit that can be implemented in a quantum robot. Here we investigate the scheme of Raghuvanshi et al. and propose a new quantum circuit to make the quantum robot fly. We demonstrate one of its applications in playing a game. The quantum robot we present here shows the behaviour of ‘fear’, and its movement is deterministic in nature. This phenomenon can be successfully modelled in a game, where it can always avoid accident. The proposed quantum circuit is designed in IBM quantum experience describing the above protocol.

##### Physical Review Letters

- Universal First-Passage-Time Distribution of Non-Gaussian Currents by Shilpi Singh, Paul Menczel, Dmitry S. Golubev, Ivan M. Khaymovich, Joonas T. Peltonen, Christian Flindt, Keiji Saito, Édgar Roldán, and Jukka P. Pekola (2019/06/13 12:00)Author(s): Shilpi Singh, Paul Menczel, Dmitry S. Golubev, Ivan M. Khaymovich, Joonas T. Peltonen, Christian Flindt, Keiji Saito, Édgar Roldán, and Jukka P. Pekola
We investigate the fluctuations of the time elapsed until the electric charge transferred through a conductor reaches a given threshold value. For this purpose, we measure the distribution of the first-passage times for the net number of electrons transferred between two metallic islands in the Coul...

[Phys. Rev. Lett. 122, 230602] Published Thu Jun 13, 2019 - Dynamical Fractal in Quantum Gases with Discrete Scaling Symmetry by Chao Gao, Hui Zhai, and Zhe-Yu Shi (2019/06/12 12:00)Author(s): Chao Gao, Hui Zhai, and Zhe-Yu Shi
Inspired by the similarity between the fractal Weierstrass function and quantum systems with discrete scaling symmetry, we establish general conditions under which the dynamics of a quantum system will exhibit fractal structure in the time domain. As an example, we discuss the dynamics of the Loschm...

[Phys. Rev. Lett. 122, 230402] Published Wed Jun 12, 2019 - Quantum Computation of Electronic Transitions Using a Variational Quantum Eigensolver by Robert M. Parrish, Edward G. Hohenstein, Peter L. McMahon, and Todd J. Martínez (2019/06/12 12:00)Author(s): Robert M. Parrish, Edward G. Hohenstein, Peter L. McMahon, and Todd J. Martínez
We develop an extension of the variational quantum eigensolver (VQE) algorithm—multistate contracted VQE (MC-VQE)—that allows for the efficient computation of the transition energies between the ground state and several low-lying excited states of a molecule, as well as the oscillator strengths asso...

[Phys. Rev. Lett. 122, 230401] Published Wed Jun 12, 2019 - Higher-Dimensional Quantum Hypergraph-Product Codes with Finite Rates by Weilei Zeng and Leonid P. Pryadko (2019/06/11 12:00)Author(s): Weilei Zeng and Leonid P. Pryadko
We describe a family of quantum error-correcting codes which generalize both the quantum hypergraph-product codes by Tillich and Zémor and all families of toric codes on $m$-dimensional hypercubic lattices. Parameters of the constructed codes, including the minimum distances, are given explicitly in...

[Phys. Rev. Lett. 122, 230501] Published Tue Jun 11, 2019 - Operationally Accessible Bounds on Fluctuations and Entropy Production in Periodically Driven Systems by Timur Koyuk and Udo Seifert (2019/06/11 12:00)Author(s): Timur Koyuk and Udo Seifert
For periodically driven systems, we derive a family of inequalities that relate entropy production with experimentally accessible data for the mean, its dependence on driving frequency, and the variance of a large class of observables. With one of these relations, overall entropy production can be b...

[Phys. Rev. Lett. 122, 230601] Published Tue Jun 11, 2019 - Eigenstate Correlations, Thermalization, and the Butterfly Effect by Amos Chan, Andrea De Luca, and J. T. Chalker (2019/06/07 12:00)Author(s): Amos Chan, Andrea De Luca, and J. T. Chalker
We discuss eigenstate correlations for ergodic, spatially extended many-body quantum systems, in terms of the statistical properties of matrix elements of local observables. While the eigenstate thermalization hypothesis (ETH) is known to give an excellent description of these quantities, the phenom...

[Phys. Rev. Lett. 122, 220601] Published Fri Jun 07, 2019 - Emergent SU(2) Dynamics and Perfect Quantum Many-Body Scars by Soonwon Choi, Christopher J. Turner, Hannes Pichler, Wen Wei Ho, Alexios A. Michailidis, Zlatko Papić, Maksym Serbyn, Mikhail D. Lukin, and Dmitry A. Abanin (2019/06/07 12:00)Author(s): Soonwon Choi, Christopher J. Turner, Hannes Pichler, Wen Wei Ho, Alexios A. Michailidis, Zlatko Papić, Maksym Serbyn, Mikhail D. Lukin, and Dmitry A. Abanin
Long-lived dynamics in a constrained spin model suggests that quantum scars are stable in the thermodynamic limit.

[Phys. Rev. Lett. 122, 220603] Published Fri Jun 07, 2019 - Novel Technique for Robust Optimal Algorithmic Cooling by Sadegh Raeisi, Mária Kieferová, and Michele Mosca (2019/06/07 12:00)Author(s): Sadegh Raeisi, Mária Kieferová, and Michele Mosca
Heat-bath algorithmic cooling provides algorithmic ways to improve the purity of quantum states. These techniques are complex iterative processes that change from each iteration to the next and this poses a significant challenge to implementing these algorithms. Here, we introduce a new technique th...

[Phys. Rev. Lett. 122, 220501] Published Fri Jun 07, 2019 - Quantum Martingale Theory and Entropy Production by Gonzalo Manzano, Rosario Fazio, and Édgar Roldán (2019/06/07 12:00)Author(s): Gonzalo Manzano, Rosario Fazio, and Édgar Roldán
We employ martingale theory to describe fluctuations of entropy production for open quantum systems in nonequilbrium steady states. Using the formalism of quantum jump trajectories, we identify a decomposition of entropy production into an exponential martingale and a purely quantum term, both obeyi...

[Phys. Rev. Lett. 122, 220602] Published Fri Jun 07, 2019 - Entanglement Detection by Violations of Noisy Uncertainty Relations: A Proof of Principle by Yuan-Yuan Zhao, Guo-Yong Xiang, Xiao-Min Hu, Bi-Heng Liu, Chuan-Feng Li, Guang-Can Guo, René Schwonnek, and Ramona Wolf (2019/06/07 12:00)Author(s): Yuan-Yuan Zhao, Guo-Yong Xiang, Xiao-Min Hu, Bi-Heng Liu, Chuan-Feng Li, Guang-Can Guo, René Schwonnek, and Ramona Wolf
It is well known that the violation of a local uncertainty relation can be used as an indicator for the presence of entanglement. Unfortunately, the practical use of these nonlinear witnesses has been limited to few special cases in the past. However, new methods for computing uncertainty bounds hav...

[Phys. Rev. Lett. 122, 220401] Published Fri Jun 07, 2019 - Machine Learning Topological Phases with a Solid-State Quantum Simulator by Wenqian Lian, Sheng-Tao Wang, Sirui Lu, Yuanyuan Huang, Fei Wang, Xinxing Yuan, Wengang Zhang, Xiaolong Ouyang, Xin Wang, Xianzhi Huang, Li He, Xiuying Chang, Dong-Ling Deng, and Luming Duan (2019/05/31 12:00)Author(s): Wenqian Lian, Sheng-Tao Wang, Sirui Lu, Yuanyuan Huang, Fei Wang, Xinxing Yuan, Wengang Zhang, Xiaolong Ouyang, Xin Wang, Xianzhi Huang, Li He, Xiuying Chang, Dong-Ling Deng, and Luming Duan
We report an experimental demonstration of a machine learning approach to identify exotic topological phases, with a focus on the three-dimensional chiral topological insulators. We show that the convolutional neural networks—a class of deep feed-forward artificial neural networks with widespread ap...

[Phys. Rev. Lett. 122, 210503] Published Fri May 31, 2019 - Kardar-Parisi-Zhang Physics in the Quantum Heisenberg Magnet by Marko Ljubotina, Marko Žnidarič, and Tomaž Prosen (2019/05/31 12:00)Author(s): Marko Ljubotina, Marko Žnidarič, and Tomaž Prosen
Equilibrium spatiotemporal correlation functions are central to understanding weak nonequilibrium physics. In certain local one-dimensional classical systems with three conservation laws they show universal features. Namely, fluctuations around ballistically propagating sound modes can be described ...

[Phys. Rev. Lett. 122, 210602] Published Fri May 31, 2019 - Dissipative Charging of a Quantum Battery by Felipe Barra (2019/05/30 12:00)Author(s): Felipe Barra
We show that a cyclic unitary process can extract work from the thermodynamic equilibrium state of an engineered quantum dissipative process. Systems in the equilibrium states of these processes serve as batteries, storing energy. The dissipative process that brings the battery to the active equilib...

[Phys. Rev. Lett. 122, 210601] Published Thu May 30, 2019 - Experimental Measurement of the Quantum Metric Tensor and Related Topological Phase Transition with a Superconducting Qubit by Xinsheng Tan, Dan-Wei Zhang, Zhen Yang, Ji Chu, Yan-Qing Zhu, Danyu Li, Xiaopei Yang, Shuqing Song, Zhikun Han, Zhiyuan Li, Yuqian Dong, Hai-Feng Yu, Hui Yan, Shi-Liang Zhu, and Yang Yu (2019/05/29 12:00)Author(s): Xinsheng Tan, Dan-Wei Zhang, Zhen Yang, Ji Chu, Yan-Qing Zhu, Danyu Li, Xiaopei Yang, Shuqing Song, Zhikun Han, Zhiyuan Li, Yuqian Dong, Hai-Feng Yu, Hui Yan, Shi-Liang Zhu, and Yang Yu
A Berry curvature is an imaginary component of the quantum geometric tensor (QGT) and is well studied in many branches of modern physics; however, the quantum metric as a real component of the QGT is less explored. Here, by using tunable superconducting circuits, we experimentally demonstrate two me...

[Phys. Rev. Lett. 122, 210401] Published Wed May 29, 2019 - Quantum Storage of Single-Photon and Two-Photon Fock States with an All-Optical Quantum Memory by M. Bouillard, G. Boucher, J. Ferrer Ortas, B. Pointard, and R. Tualle-Brouri (2019/05/29 12:00)Author(s): M. Bouillard, G. Boucher, J. Ferrer Ortas, B. Pointard, and R. Tualle-Brouri
Quantum memories are a crucial element toward efficient quantum protocols. In the continuous variables domain, such memories need to provide high fidelity with an efficiency set to one. Moreover, one needs to store complex quantum states exhibiting negative Wigner functions after storage. We report ...

[Phys. Rev. Lett. 122, 210501] Published Wed May 29, 2019 - Sample Complexity of Device-Independently Certified “Quantum Supremacy” by Dominik Hangleiter, Martin Kliesch, Jens Eisert, and Christian Gogolin (2019/05/29 12:00)Author(s): Dominik Hangleiter, Martin Kliesch, Jens Eisert, and Christian Gogolin
Results on the hardness of approximate sampling are seen as important stepping stones toward a convincing demonstration of the superior computational power of quantum devices. The most prominent suggestions for such experiments include boson sampling, instantaneous quantum polynomial time (IQP) circ...

[Phys. Rev. Lett. 122, 210502] Published Wed May 29, 2019 - Von Neumann Entropy from Unitarity by Paul Boes, Jens Eisert, Rodrigo Gallego, Markus P. Müller, and Henrik Wilming (2019/05/28 12:00)Author(s): Paul Boes, Jens Eisert, Rodrigo Gallego, Markus P. Müller, and Henrik Wilming
The von Neumann entropy is a key quantity in quantum information theory and, roughly speaking, quantifies the amount of quantum information contained in a state when many identical and independent (i.i.d.) copies of the state are available, in a regime that is often referred to as being asymptotic. ...

[Phys. Rev. Lett. 122, 210402] Published Tue May 28, 2019 - Metric-Torsion Duality of Optically Chiral Structures by Yongliang Zhang, Lina Shi, Ruo-Yang Zhang, Jinglai Duan, Jack Ng, C. T. Chan, and Kin Hung Fung (2019/05/24 12:00)Author(s): Yongliang Zhang, Lina Shi, Ruo-Yang Zhang, Jinglai Duan, Jack Ng, C. T. Chan, and Kin Hung Fung
We develop a metric-torsion theory for chiral structures by using a generalized framework of transformation optics. We show that the chirality is uniquely determined by a metric with the local rotational degree of freedom. In analogy to the dislocation continuum, the chirality can be alternatively i...

[Phys. Rev. Lett. 122, 200201] Published Fri May 24, 2019 - Thermodynamic Capacity of Quantum Processes by Philippe Faist, Mario Berta, and Fernando Brandão (2019/05/24 12:00)Author(s): Philippe Faist, Mario Berta, and Fernando Brandão
Thermodynamics imposes restrictions on what state transformations are possible. In the macroscopic limit of asymptotically many independent copies of a state—as for instance in the case of an ideal gas—the possible transformations become reversible and are fully characterized by the free energy. In ...

[Phys. Rev. Lett. 122, 200601] Published Fri May 24, 2019 - Randomization of Pulse Phases for Unambiguous and Robust Quantum Sensing by Zhen-Yu Wang, Jacob E. Lang, Simon Schmitt, Johannes Lang, Jorge Casanova, Liam McGuinness, Tania S. Monteiro, Fedor Jelezko, and Martin B. Plenio (2019/05/24 12:00)Author(s): Zhen-Yu Wang, Jacob E. Lang, Simon Schmitt, Johannes Lang, Jorge Casanova, Liam McGuinness, Tania S. Monteiro, Fedor Jelezko, and Martin B. Plenio
We develop theoretically and demonstrate experimentally a universal dynamical decoupling method for robust quantum sensing with unambiguous signal identification. Our method uses randomization of control pulses to simultaneously suppress two types of errors in the measured spectra that would otherwi...

[Phys. Rev. Lett. 122, 200403] Published Fri May 24, 2019 - Coherent Superposition of Feshbach Dimers and Efimov Trimers by Yaakov Yudkin, Roy Elbaz, P. Giannakeas, Chris H. Greene, and Lev Khaykovich (2019/05/24 12:00)Author(s): Yaakov Yudkin, Roy Elbaz, P. Giannakeas, Chris H. Greene, and Lev Khaykovich
A powerful experimental technique to study Efimov physics at positive scattering lengths is demonstrated. We use the Feshbach dimers as a local reference for Efimov trimers by creating a coherent superposition of both states. Measurement of its coherent evolution provides information on the binding ...

[Phys. Rev. Lett. 122, 200402] Published Fri May 24, 2019 - Three-Qubit Randomized Benchmarking by David C. McKay, Sarah Sheldon, John A. Smolin, Jerry M. Chow, and Jay M. Gambetta (2019/05/23 12:00)Author(s): David C. McKay, Sarah Sheldon, John A. Smolin, Jerry M. Chow, and Jay M. Gambetta
As quantum circuits increase in size, it is critical to establish scalable multiqubit fidelity metrics. Here we investigate, for the first time, three-qubit randomized benchmarking (RB) on a quantum device consisting of three fixed-frequency transmon qubits with pairwise microwave-activated interact...

[Phys. Rev. Lett. 122, 200502] Published Thu May 23, 2019 - Neural Belief-Propagation Decoders for Quantum Error-Correcting Codes by Ye-Hua Liu and David Poulin (2019/05/22 12:00)Author(s): Ye-Hua Liu and David Poulin
Belief-propagation (BP) decoders play a vital role in modern coding theory, but they are not suitable to decode quantum error-correcting codes because of a unique quantum feature called error degeneracy. Inspired by an exact mapping between BP and deep neural networks, we train neural BP decoders fo...

[Phys. Rev. Lett. 122, 200501] Published Wed May 22, 2019 - Machine Learning Nonlocal Correlations by Askery Canabarro, Samuraí Brito, and Rafael Chaves (2019/05/22 12:00)Author(s): Askery Canabarro, Samuraí Brito, and Rafael Chaves
The ability to witness nonlocal correlations lies at the core of foundational aspects of quantum mechanics and its application in the processing of information. Commonly, this is achieved via the violation of Bell inequalities. Unfortunately, however, their systematic derivation quickly becomes unfe...

[Phys. Rev. Lett. 122, 200401] Published Wed May 22, 2019 - Initialization and Readout of Nuclear Spins via a Negatively Charged Silicon-Vacancy Center in Diamond by Mathias H. Metsch, Katharina Senkalla, Benedikt Tratzmiller, Jochen Scheuer, Michael Kern, Jocelyn Achard, Alexandre Tallaire, Martin B. Plenio, Petr Siyushev, and Fedor Jelezko (2019/05/17 12:00)Author(s): Mathias H. Metsch, Katharina Senkalla, Benedikt Tratzmiller, Jochen Scheuer, Michael Kern, Jocelyn Achard, Alexandre Tallaire, Martin B. Plenio, Petr Siyushev, and Fedor Jelezko
In this Letter, we demonstrate initialization and readout of nuclear spins via a negatively charged silicon-vacancy (SiV) electron spin qubit. Under Hartmann-Hahn conditions the electron spin polarization is coherently transferred to the nuclear spin. The readout of the nuclear polarization is obser...

[Phys. Rev. Lett. 122, 190503] Published Fri May 17, 2019 - Quantifying Operations with an Application to Coherence by Thomas Theurer, Dario Egloff, Lijian Zhang, and Martin B. Plenio (2019/05/17 12:00)Author(s): Thomas Theurer, Dario Egloff, Lijian Zhang, and Martin B. Plenio
To describe certain facets of nonclassicality, it is necessary to quantify properties of operations instead of states. This is the case if one wants to quantify how well an operation detects nonclassicality, which is a necessary prerequisite for its use in quantum technologies. To do so rigorously, ...

[Phys. Rev. Lett. 122, 190405] Published Fri May 17, 2019 - Complexity of Causal Order Structure in Distributed Quantum Information Processing: More Rounds of Classical Communication Reduce Entanglement Cost by Eyuri Wakakuwa, Akihito Soeda, and Mio Murao (2019/05/16 12:00)Author(s): Eyuri Wakakuwa, Akihito Soeda, and Mio Murao
We prove a trade-off relation between the entanglement cost and classical communication round complexity of a protocol in implementing a class of two-qubit unitary gates by two distant parties, a key subroutine in distributed quantum information processing. The task is analyzed in an information the...

[Phys. Rev. Lett. 122, 190502] Published Thu May 16, 2019 - Prospect of Studying Nonperturbative QED with Beam-Beam Collisions by V. Yakimenko, S. Meuren, F. Del Gaudio, C. Baumann, A. Fedotov, F. Fiuza, T. Grismayer, M. J. Hogan, A. Pukhov, L. O. Silva, and G. White (2019/05/16 12:00)Author(s): V. Yakimenko, S. Meuren, F. Del Gaudio, C. Baumann, A. Fedotov, F. Fiuza, T. Grismayer, M. J. Hogan, A. Pukhov, L. O. Silva, and G. White
We demonstrate the experimental feasibility of probing the fully nonperturbative regime of quantum electrodynamics with a 100 GeV-class particle collider. By using tightly compressed and focused electron beams, beamstrahlung radiation losses can be mitigated, allowing the particles to experience ext...

[Phys. Rev. Lett. 122, 190404] Published Thu May 16, 2019 - Multielectron Ground State Electroluminescence by Mauro Cirio, Nathan Shammah, Neill Lambert, Simone De Liberato, and Franco Nori (2019/05/15 12:00)Author(s): Mauro Cirio, Nathan Shammah, Neill Lambert, Simone De Liberato, and Franco Nori
The ground state of a cavity-electron system in the ultrastrong coupling regime is characterized by the presence of virtual photons. If an electric current flows through this system, the modulation of the light-matter coupling induced by this nonequilibrium effect can induce an extracavity photon em...

[Phys. Rev. Lett. 122, 190403] Published Wed May 15, 2019 - Quantum State Smoothing for Linear Gaussian Systems by Kiarn T. Laverick, Areeya Chantasri, and Howard M. Wiseman (2019/05/15 12:00)Author(s): Kiarn T. Laverick, Areeya Chantasri, and Howard M. Wiseman
Quantum state smoothing is a technique for assigning a valid quantum state to a partially observed dynamical system, using measurement records both prior and posterior to an estimation time. We show that the technique is greatly simplified for linear Gaussian quantum systems, which have wide physica...

[Phys. Rev. Lett. 122, 190402] Published Wed May 15, 2019 - Confidence Polytopes in Quantum State Tomography by Jinzhao Wang, Volkher B. Scholz, and Renato Renner (2019/05/15 12:00)Author(s): Jinzhao Wang, Volkher B. Scholz, and Renato Renner
Quantum state tomography is the task of inferring the state of a quantum system from measurement data. A reliable tomography scheme should not only report an estimate for that state, but also well-justified error bars. These may be specified in terms of confidence regions, i.e., subsets of the state...

[Phys. Rev. Lett. 122, 190401] Published Wed May 15, 2019 - Single-Shot Holographic Compression from the Area Law by H. Wilming and J. Eisert (2019/05/15 12:00)Author(s): H. Wilming and J. Eisert
The area law conjecture states that the entanglement entropy of a region of space in the ground state of a gapped, local Hamiltonian only grows like the surface area of the region. We show that, for any state that fulfills an area law, the reduced quantum state of a region of space can be unitarily ...

[Phys. Rev. Lett. 122, 190501] Published Wed May 15, 2019 - Supersolid-Based Gravimeter in a Ring Cavity by Karol Gietka, Farokh Mivehvar, and Helmut Ritsch (2019/05/13 12:00)Author(s): Karol Gietka, Farokh Mivehvar, and Helmut Ritsch
We propose a novel type of composite light-matter interferometer based on a supersolidlike phase of a driven Bose-Einstein condensate coupled to a pair of degenerate counterpropagating electromagnetic modes of an optical ring cavity. The supersolidlike condensate under the influence of the gravity d...

[Phys. Rev. Lett. 122, 190801] Published Mon May 13, 2019 - Exactly Solvable Points and Symmetry Protected Topological Phases of Quantum Spins on a Zig-Zag Lattice by Haiyuan Zou, Erhai Zhao, Xi-Wen Guan, and W. Vincent Liu (2019/05/10 12:00)Author(s): Haiyuan Zou, Erhai Zhao, Xi-Wen Guan, and W. Vincent Liu
A large number of symmetry-protected topological (SPT) phases have been hypothesized for strongly interacting $\mathrm{spin}\text{−}1/2$ systems in one dimension. Realizing these SPT phases, however, often demands fine-tunings hard to reach experimentally. And the lack of analytical solutions hinder...

[Phys. Rev. Lett. 122, 180401] Published Fri May 10, 2019 - Random Matrix Ensemble for the Level Statistics of Many-Body Localization by Wouter Buijsman, Vadim Cheianov, and Vladimir Gritsev (2019/05/10 12:00)Author(s): Wouter Buijsman, Vadim Cheianov, and Vladimir Gritsev
We numerically study the level statistics of the Gaussian $β$ ensemble. These statistics generalize Wigner-Dyson level statistics from the discrete set of Dyson indices $β=1$, 2, 4 to the continuous range $0<β<∞$. The Gaussian $β$ ensemble covers Poissonian level statistics for $β→0$, and prov...

[Phys. Rev. Lett. 122, 180601] Published Fri May 10, 2019 - Classical Lieb-Robinson Bound for Estimating Equilibration Timescales of Isolated Quantum Systems by Daniel Nickelsen and Michael Kastner (2019/05/10 12:00)Author(s): Daniel Nickelsen and Michael Kastner
We study equilibration of an isolated quantum system by mapping it onto a network of classical oscillators in Hilbert space. By choosing a suitable basis for this mapping, the degree of locality of the quantum system reflects in the sparseness of the network. We derive a Lieb-Robinson bound on the s...

[Phys. Rev. Lett. 122, 180602] Published Fri May 10, 2019 - Error-Mitigated Digital Quantum Simulation by Sam McArdle, Xiao Yuan, and Simon Benjamin (2019/05/08 12:00)Author(s): Sam McArdle, Xiao Yuan, and Simon Benjamin
Variational algorithms may enable classically intractable simulations on near-future quantum computers. However, their potential is limited by hardware errors. It is therefore crucial to develop efficient ways to mitigate these errors. Here, we propose a stabilizerlike method which enables the detec...

[Phys. Rev. Lett. 122, 180501] Published Wed May 08, 2019 - Optimal Probabilistic Storage and Retrieval of Unitary Channels by Michal Sedlák, Alessandro Bisio, and Mário Ziman (2019/05/03 12:00)Author(s): Michal Sedlák, Alessandro Bisio, and Mário Ziman
We address the question of quantum memory storage for quantum dynamics. In particular, we design an optimal protocol for $N→1$ probabilistic storage and retrieval of unitary channels on $d$-dimensional quantum systems. If we access the unknown unitary gate only $N$ times, the optimal success probabi...

[Phys. Rev. Lett. 122, 170502] Published Fri May 03, 2019 - Observation of Many-Body Localization in a One-Dimensional System with a Single-Particle Mobility Edge by Thomas Kohlert, Sebastian Scherg, Xiao Li, Henrik P. Lüschen, Sankar Das Sarma, Immanuel Bloch, and Monika Aidelsburger (2019/05/03 12:00)Author(s): Thomas Kohlert, Sebastian Scherg, Xiao Li, Henrik P. Lüschen, Sankar Das Sarma, Immanuel Bloch, and Monika Aidelsburger
We experimentally study many-body localization (MBL) with ultracold atoms in a weak one-dimensional quasiperiodic potential, which in the noninteracting limit exhibits an intermediate phase that is characterized by a mobility edge. We measure the time evolution of an initial charge density wave afte...

[Phys. Rev. Lett. 122, 170403] Published Fri May 03, 2019 - Prescaling in a Far-from-Equilibrium Bose Gas by Christian-Marcel Schmied, Aleksandr N. Mikheev, and Thomas Gasenzer (2019/05/03 12:00)Author(s): Christian-Marcel Schmied, Aleksandr N. Mikheev, and Thomas Gasenzer
Nonequilibrium conditions give rise to classes of universally evolving configurations of quantum many-body systems at nonthermal fixed points. While the fixed point and thus full scaling in space and time is generically reached at very long evolution times, we propose that systems can show prescalin...

[Phys. Rev. Lett. 122, 170404] Published Fri May 03, 2019 - Quantum Spin Dynamics in Fock Space Following Quenches: Caustics and Vortices by J. Mumford, E. Turner, D. W. L. Sprung, and D. H. J. O’Dell (2019/05/03 12:00)Author(s): J. Mumford, E. Turner, D. W. L. Sprung, and D. H. J. O’Dell
Caustics occur widely in dynamics and take on shapes classified by catastrophe theory. At finite wavelengths they produce interference patterns containing networks of vortices (phase singularities). Here we investigate caustics in quantized fields, focusing on the collective dynamics of quantum spin...

[Phys. Rev. Lett. 122, 170402] Published Fri May 03, 2019 - Demonstration of Controlled Quantum Teleportation for Discrete Variables on Linear Optical Devices by Artur Barasiński, Antonín Černoch, and Karel Lemr (2019/04/29 12:00)Author(s): Artur Barasiński, Antonín Černoch, and Karel Lemr
We report an experimental implementation of tripartite controlled quantum teleportation on quantum optical devices. The protocol is performed through bi- and tripartite entangled channels of discrete variables and qubits encoded in the polarization of individual photons. The experimental results dem...

[Phys. Rev. Lett. 122, 170501] Published Mon Apr 29, 2019 - Experimental Demonstration of High-Rate Measurement-Device-Independent Quantum Key Distribution over Asymmetric Channels by Hui Liu, Wenyuan Wang, Kejin Wei, Xiao-Tian Fang, Li Li, Nai-Le Liu, Hao Liang, Si-Jie Zhang, Weijun Zhang, Hao Li, Lixing You, Zhen Wang, Hoi-Kwong Lo, Teng-Yun Chen, Feihu Xu, and Jian-Wei Pan (2019/04/26 12:00)Author(s): Hui Liu, Wenyuan Wang, Kejin Wei, Xiao-Tian Fang, Li Li, Nai-Le Liu, Hao Liang, Si-Jie Zhang, Weijun Zhang, Hao Li, Lixing You, Zhen Wang, Hoi-Kwong Lo, Teng-Yun Chen, Feihu Xu, and Jian-Wei Pan
Measurement-device-independent quantum key distribution (MDI-QKD) can eliminate all detector side channels and it is practical with current technology. Previous implementations of MDI-QKD all used two symmetric channels with similar losses. However, the secret key rate is severely limited when diffe...

[Phys. Rev. Lett. 122, 160501] Published Fri Apr 26, 2019 - Probing the Full Distribution of Many-Body Observables By Single-Qubit Interferometry by Zhenyu Xu and Adolfo del Campo (2019/04/26 12:00)Author(s): Zhenyu Xu and Adolfo del Campo
We present an experimental scheme to measure the full distribution of many-body observables in spin systems, both in and out of equilibrium, using an auxiliary qubit as a probe. We focus on the determination of the magnetization and the kink number statistics at thermal equilibrium. The correspondin...

[Phys. Rev. Lett. 122, 160602] Published Fri Apr 26, 2019 - Cluster State Generation with Spin-Orbit Coupled Fermionic Atoms in Optical Lattices by M. Mamaev, R. Blatt, J. Ye, and A. M. Rey (2019/04/24 12:00)Author(s): M. Mamaev, R. Blatt, J. Ye, and A. M. Rey
Measurement-based quantum computation, an alternative paradigm for quantum information processing, uses simple measurements on qubits prepared in cluster states, a class of multiparty entangled states with useful properties. Here we propose and analyze a scheme that takes advantage of the interplay ...

[Phys. Rev. Lett. 122, 160402] Published Wed Apr 24, 2019 - Material Size Dependence on Fundamental Constants by Lukáš F. Pašteka, Yongliang Hao, Anastasia Borschevsky, Victor V. Flambaum, and Peter Schwerdtfeger (2019/04/24 12:00)Author(s): Lukáš F. Pašteka, Yongliang Hao, Anastasia Borschevsky, Victor V. Flambaum, and Peter Schwerdtfeger
Searching for variations in fundamental constants—which are predicted by some theories of dark matter—might potentially be done by monitoring the sizes of solid crystals.

[Phys. Rev. Lett. 122, 160801] Published Wed Apr 24, 2019 - Kinked Entropy and Discontinuous Microcanonical Spontaneous Symmetry Breaking by Hai-Jun Zhou (2019/04/24 12:00)Author(s): Hai-Jun Zhou
Spontaneous symmetry breaking (SSB) in statistical physics is a macroscopic collective phenomenon. For the paradigmatic $Q$-state Potts model it means a transition from the disordered color-symmetric phase to an ordered phase in which one color dominates. Existing mean field theories imply that SSB ...

[Phys. Rev. Lett. 122, 160601] Published Wed Apr 24, 2019 - Simulation Complexity of Open Quantum Dynamics: Connection with Tensor Networks by I. A. Luchnikov, S. V. Vintskevich, H. Ouerdane, and S. N. Filippov (2019/04/23 12:00)Author(s): I. A. Luchnikov, S. V. Vintskevich, H. Ouerdane, and S. N. Filippov
The difficulty to simulate the dynamics of open quantum systems resides in their coupling to many-body reservoirs with exponentially large Hilbert space. Applying a tensor network approach in the time domain, we demonstrate that effective small reservoirs can be defined and used for modeling open qu...

[Phys. Rev. Lett. 122, 160401] Published Tue Apr 23, 2019 - Generic Bound Coherence under Strictly Incoherent Operations by Ludovico Lami, Bartosz Regula, and Gerardo Adesso (2019/04/19 12:00)Author(s): Ludovico Lami, Bartosz Regula, and Gerardo Adesso
We compute analytically the maximal rates of distillation of quantum coherence under strictly incoherent operations (SIO) and physically incoherent operations (PIO), showing that they coincide for all states, and providing a complete description of the phenomenon of bound coherence. In particular, w...

[Phys. Rev. Lett. 122, 150402] Published Fri Apr 19, 2019 - Entanglement-Guided Search for Parent Hamiltonians by X. Turkeshi, T. Mendes-Santos, G. Giudici, and M. Dalmonte (2019/04/19 12:00)Author(s): X. Turkeshi, T. Mendes-Santos, G. Giudici, and M. Dalmonte
We introduce a method for the search of parent Hamiltonians of input wave functions based on the structure of their reduced density matrix. The two key elements of our recipe are an ansatz on the relation between the reduced density matrix and parent Hamiltonian that is exact at the field theory lev...

[Phys. Rev. Lett. 122, 150606] Published Fri Apr 19, 2019 - Ballistic Spin Transport in a Periodically Driven Integrable Quantum System by Marko Ljubotina, Lenart Zadnik, and Tomaž Prosen (2019/04/19 12:00)Author(s): Marko Ljubotina, Lenart Zadnik, and Tomaž Prosen
We demonstrate ballistic spin transport of an integrable unitary quantum circuit, which can be understood either as a paradigm of an integrable periodically driven (Floquet) spin chain, or as a Trotterized anisotropic ($XXZ$) Heisenberg spin-$1/2$ model. We construct an analytic family of quasilocal...

[Phys. Rev. Lett. 122, 150605] Published Fri Apr 19, 2019 - Optimal Probabilistic Work Extraction beyond the Free Energy Difference with a Single-Electron Device by Olivier Maillet, Paolo A. Erdman, Vasco Cavina, Bibek Bhandari, Elsa T. Mannila, Joonas T. Peltonen, Andrea Mari, Fabio Taddei, Christopher Jarzynski, Vittorio Giovannetti, and Jukka P. Pekola (2019/04/18 12:00)Author(s): Olivier Maillet, Paolo A. Erdman, Vasco Cavina, Bibek Bhandari, Elsa T. Mannila, Joonas T. Peltonen, Andrea Mari, Fabio Taddei, Christopher Jarzynski, Vittorio Giovannetti, and Jukka P. Pekola
In very small systems like a single electron transistor, sometimes thermal fluctuations allow single shot extraction of work from the system beyond the bounds of the second law of thermodynamics.

[Phys. Rev. Lett. 122, 150604] Published Thu Apr 18, 2019 - Confined Quasiparticle Dynamics in Long-Range Interacting Quantum Spin Chains by Fangli Liu, Rex Lundgren, Paraj Titum, Guido Pagano, Jiehang Zhang, Christopher Monroe, and Alexey V. Gorshkov (2019/04/16 12:00)Author(s): Fangli Liu, Rex Lundgren, Paraj Titum, Guido Pagano, Jiehang Zhang, Christopher Monroe, and Alexey V. Gorshkov
We study the quasiparticle excitation and quench dynamics of the one-dimensional transverse-field Ising model with power-law ($1/{r}^{α}$) interactions. We find that long-range interactions give rise to a confining potential, which couples pairs of domain walls (kinks) into bound quasiparticles, ana...

[Phys. Rev. Lett. 122, 150601] Published Tue Apr 16, 2019 - Dynamical Computation of the Density of States and Bayes Factors Using Nonequilibrium Importance Sampling by Grant M. Rotskoff and Eric Vanden-Eijnden (2019/04/16 12:00)Author(s): Grant M. Rotskoff and Eric Vanden-Eijnden
Nonequilibrium sampling is potentially much more versatile than its equilibrium counterpart, but it comes with challenges because the invariant distribution is not typically known when the dynamics breaks detailed balance. Here, we derive a generic importance sampling technique that leverages the st...

[Phys. Rev. Lett. 122, 150602] Published Tue Apr 16, 2019 - Thermodynamics of Quantum Information Flows by Krzysztof Ptaszyński and Massimiliano Esposito (2019/04/16 12:00)Author(s): Krzysztof Ptaszyński and Massimiliano Esposito
We report two results complementing the second law of thermodynamics for Markovian open quantum systems coupled to multiple reservoirs with different temperatures and chemical potentials. First, we derive a nonequilibrium free energy inequality providing an upper bound for a maximum power output, wh...

[Phys. Rev. Lett. 122, 150603] Published Tue Apr 16, 2019 - Breaking the Fluctuation-Dissipation Relation by Universal Transport Processes by Asier Piñeiro Orioli and Jürgen Berges (2019/04/15 12:00)Author(s): Asier Piñeiro Orioli and Jürgen Berges
Universal phenomena far from equilibrium exhibit additional independent scaling exponents and functions as compared to thermal universal behavior. For the example of an ultracold Bose gas we simulate nonequilibrium transport processes in a universal scaling regime and show how they lead to the break...

[Phys. Rev. Lett. 122, 150401] Published Mon Apr 15, 2019 - Accelerated Variational Quantum Eigensolver by Daochen Wang, Oscar Higgott, and Stephen Brierley (2019/04/12 12:00)Author(s): Daochen Wang, Oscar Higgott, and Stephen Brierley
The problem of finding the ground state energy of a Hamiltonian using a quantum computer is currently solved using either the quantum phase estimation (QPE) or variational quantum eigensolver (VQE) algorithms. For precision $ε$, QPE requires $O(1)$ repetitions of circuits with depth $O(1/ε)$, wherea...

[Phys. Rev. Lett. 122, 140504] Published Fri Apr 12, 2019 - Spurious Topological Entanglement Entropy from Subsystem Symmetries by Dominic J. Williamson, Arpit Dua, and Meng Cheng (2019/04/12 12:00)Author(s): Dominic J. Williamson, Arpit Dua, and Meng Cheng
We demonstrate that linear combinations of subregion entropies with canceling boundary terms, commonly used to calculate the topological entanglement entropy, may suffer from spurious nontopological contributions even in models with zero correlation length. These spurious contributions are due to a ...

[Phys. Rev. Lett. 122, 140506] Published Fri Apr 12, 2019 - Towards Superresolution Surface Metrology: Quantum Estimation of Angular and Axial Separations by Carmine Napoli, Samanta Piano, Richard Leach, Gerardo Adesso, and Tommaso Tufarelli (2019/04/12 12:00)Author(s): Carmine Napoli, Samanta Piano, Richard Leach, Gerardo Adesso, and Tommaso Tufarelli
We investigate the localization of two incoherent point sources with arbitrary angular and axial separations in the paraxial approximation. By using quantum metrology techniques, we show that a simultaneous estimation of the two separations is achievable by a single quantum measurement, with a preci...

[Phys. Rev. Lett. 122, 140505] Published Fri Apr 12, 2019 - Contextuality and the Single-Qubit Stabilizer Subtheory by Piers Lillystone, Joel J. Wallman, and Joseph Emerson (2019/04/12 12:00)Author(s): Piers Lillystone, Joel J. Wallman, and Joseph Emerson
Contextuality is a fundamental nonclassical property of quantum theory, which has recently been proven to be a key resource for achieving quantum speed-ups in some leading models of quantum computation. However, which of the forms of contextuality, and how much thereof, are required to obtain a spee...

[Phys. Rev. Lett. 122, 140405] Published Fri Apr 12, 2019 - Operational Advantage of Quantum Resources in Subchannel Discrimination by Ryuji Takagi, Bartosz Regula, Kaifeng Bu, Zi-Wen Liu, and Gerardo Adesso (2019/04/10 12:00)Author(s): Ryuji Takagi, Bartosz Regula, Kaifeng Bu, Zi-Wen Liu, and Gerardo Adesso
New measures are defined which quantify the power of quantum resources in channel discrimination and the informativeness of quantum measurements.

[Phys. Rev. Lett. 122, 140402] Published Wed Apr 10, 2019 - Robustness of Measurement, Discrimination Games, and Accessible Information by Paul Skrzypczyk and Noah Linden (2019/04/10 12:00)Author(s): Paul Skrzypczyk and Noah Linden
New measures are defined which quantify the power of quantum resources in channel discrimination and the informativeness of quantum measurements.

[Phys. Rev. Lett. 122, 140403] Published Wed Apr 10, 2019 - More Entanglement Implies Higher Performance in Channel Discrimination Tasks by Joonwoo Bae, Dariusz Chruściński, and Marco Piani (2019/04/10 12:00)Author(s): Joonwoo Bae, Dariusz Chruściński, and Marco Piani
We show that every entangled state provides an advantage in ancilla-assisted bi- and multichannel discrimination that singles out its degree of entanglement, quantified in terms of the Schmidt number. The Schmidt-number robustness provides a compelling quantification of such an advantage, and, remar...

[Phys. Rev. Lett. 122, 140404] Published Wed Apr 10, 2019 - Non-Weyl Microwave Graphs by Michał Ławniczak, Jiří Lipovský, and Leszek Sirko (2019/04/10 12:00)Author(s): Michał Ławniczak, Jiří Lipovský, and Leszek Sirko
One of the most important characteristics of a quantum graph is the average density of resonances, $ρ=(\mathcal{L}/π)$, where $\mathcal{L}$ denotes the length of the graph. This is a very robust measure. It does not depend on the number of vertices in a graph and holds also for most of the boundary ...

[Phys. Rev. Lett. 122, 140503] Published Wed Apr 10, 2019 - Heralded Bell State of Dissipative Qubits Using Classical Light in a Waveguide by Xin H. H. Zhang and Harold U. Baranger (2019/04/09 12:00)Author(s): Xin H. H. Zhang and Harold U. Baranger
Maximally entangled two-qubit states (Bell states) are of central importance in quantum technologies. We show that heralded generation of a maximally entangled state of two intrinsically open qubits can be realized in a one-dimensional (1D) system through strong coherent driving and continuous monit...

[Phys. Rev. Lett. 122, 140502] Published Tue Apr 09, 2019 - Environment-Assisted Holonomic Quantum Maps by Nicklas Ramberg and Erik Sjöqvist (2019/04/09 12:00)Author(s): Nicklas Ramberg and Erik Sjöqvist
Holonomic quantum computation uses non-Abelian geometric phases to realize error resilient quantum gates. Nonadiabatic holonomic gates are particularly suitable to avoid unwanted decoherence effects, as they can be performed at high speed. By letting the computational system interact with a structur...

[Phys. Rev. Lett. 122, 140501] Published Tue Apr 09, 2019 - Efficiency Fluctuations in Microscopic Machines by Sreekanth K. Manikandan, Lennart Dabelow, Ralf Eichhorn, and Supriya Krishnamurthy (2019/04/09 12:00)Author(s): Sreekanth K. Manikandan, Lennart Dabelow, Ralf Eichhorn, and Supriya Krishnamurthy
Nanoscale machines are strongly influenced by thermal fluctuations, contrary to their macroscopic counterparts. As a consequence, even the efficiency of such microscopic machines becomes a fluctuating random variable. Using geometric properties and the fluctuation theorem for the total entropy produ...

[Phys. Rev. Lett. 122, 140601] Published Tue Apr 09, 2019 - Quantum Markov Order by Philip Taranto, Felix A. Pollock, Simon Milz, Marco Tomamichel, and Kavan Modi (2019/04/09 12:00)Author(s): Philip Taranto, Felix A. Pollock, Simon Milz, Marco Tomamichel, and Kavan Modi
We formally extend the notion of Markov order to open quantum processes by accounting for the instruments used to probe the system of interest at different times. Our description recovers the classical property in the appropriate limit: when the stochastic process is classical and the instruments ar...

[Phys. Rev. Lett. 122, 140401] Published Tue Apr 09, 2019 - Unraveling the Large Deviation Statistics of Markovian Open Quantum Systems by Federico Carollo, Robert L. Jack, and Juan P. Garrahan (2019/04/05 12:00)Author(s): Federico Carollo, Robert L. Jack, and Juan P. Garrahan
We analyze dynamical large deviations of quantum trajectories in Markovian open quantum systems in their full generality. We derive a quantum level-2.5 large deviation principle for these systems, which describes the joint fluctuations of time-averaged quantum jump rates and of the time-averaged qua...

[Phys. Rev. Lett. 122, 130605] Published Fri Apr 05, 2019 - Nonthermal States Arising from Confinement in One and Two Dimensions by Andrew J. A. James, Robert M. Konik, and Neil J. Robinson (2019/04/05 12:00)Author(s): Andrew J. A. James, Robert M. Konik, and Neil J. Robinson
We show that confinement in the quantum Ising model leads to nonthermal eigenstates, in both continuum and lattice theories, in both one (1D) and two dimensions (2D). In the ordered phase, the presence of a confining longitudinal field leads to a profound restructuring of the excitation spectrum, wi...

[Phys. Rev. Lett. 122, 130603] Published Fri Apr 05, 2019 - Optimal Random Deposition of Interacting Particles by Adrian Baule (2019/04/05 12:00)Author(s): Adrian Baule
Irreversible random sequential deposition of interacting particles is widely used to model aggregation phenomena in physical, chemical, and biophysical systems. We show that in one dimension the exact time-dependent solution of such processes can be found for arbitrary interaction potentials with fi...

[Phys. Rev. Lett. 122, 130602] Published Fri Apr 05, 2019 - Positivity of the Spectral Densities of Retarded Floquet Green Functions by Götz S. Uhrig, Mona H. Kalthoff, and James K. Freericks (2019/04/05 12:00)Author(s): Götz S. Uhrig, Mona H. Kalthoff, and James K. Freericks
Periodically driven nonequilibrium many-body systems are interesting because they have quasi-energy spectra, which can be tailored by controlling the external driving fields. We derive the general spectral representation of retarded Green functions in the Floquet regime, thereby generalizing the wel...

[Phys. Rev. Lett. 122, 130604] Published Fri Apr 05, 2019 - Observation of a Dipolar Quantum Gas with Metastable Supersolid Properties by L. Tanzi, E. Lucioni, F. Famà, J. Catani, A. Fioretti, C. Gabbanini, R. N. Bisset, L. Santos, and G. Modugno (2019/04/03 12:00)Author(s): L. Tanzi, E. Lucioni, F. Famà, J. Catani, A. Fioretti, C. Gabbanini, R. N. Bisset, L. Santos, and G. Modugno
A novel regime of ultracold atoms is found in which a stable density modulation, known as stripes, is observed simultaneously with quantum droplets, resulting in an important advance in the search for a dipolar supersolid.

[Phys. Rev. Lett. 122, 130405] Published Wed Apr 03, 2019 - Experimental Investigation of Quantum Decay at Short, Intermediate, and Long Times via Integrated Photonics by Andrea Crespi, Francesco V. Pepe, Paolo Facchi, Fabio Sciarrino, Paolo Mataloni, Hiromichi Nakazato, Saverio Pascazio, and Roberto Osellame (2019/04/03 12:00)Author(s): Andrea Crespi, Francesco V. Pepe, Paolo Facchi, Fabio Sciarrino, Paolo Mataloni, Hiromichi Nakazato, Saverio Pascazio, and Roberto Osellame
The decay of an unstable system is usually described by an exponential law. Quantum mechanics predicts strong deviations of the survival probability from the exponential: Indeed, the decay is initially quadratic, while at very large times it follows a power law, with superimposed oscillations. The l...

[Phys. Rev. Lett. 122, 130401] Published Wed Apr 03, 2019 - Assisted Work Distillation by Benjamin Morris, Ludovico Lami, and Gerardo Adesso (2019/04/02 12:00)Author(s): Benjamin Morris, Ludovico Lami, and Gerardo Adesso
We study the process of assisted work distillation. This scenario arises when two parties share a bipartite quantum state ${ρ}_{AB}$ and their task is to locally distill the optimal amount of work when one party is restricted to thermal operations, whereas the other can perform general quantum opera...

[Phys. Rev. Lett. 122, 130601] Published Tue Apr 02, 2019 - Quantum Incompatibility Witnesses by Claudio Carmeli, Teiko Heinosaari, and Alessandro Toigo (2019/04/02 12:00)Author(s): Claudio Carmeli, Teiko Heinosaari, and Alessandro Toigo
We demonstrate that quantum incompatibility can always be detected by means of a state discrimination task with partial intermediate information. This is done by showing that only incompatible measurements allow for an efficient use of premeasurement information in order to improve the probability o...

[Phys. Rev. Lett. 122, 130402] Published Tue Apr 02, 2019 - Quantifying Quantum Resources with Conic Programming by Roope Uola, Tristan Kraft, Jiangwei Shang, Xiao-Dong Yu, and Otfried Gühne (2019/04/02 12:00)Author(s): Roope Uola, Tristan Kraft, Jiangwei Shang, Xiao-Dong Yu, and Otfried Gühne
Resource theories can be used to formalize the quantification and manipulation of resources in quantum information processing such as entanglement, asymmetry and coherence of quantum states, and incompatibility of quantum measurements. Given a certain state or measurement, one can ask whether there ...

[Phys. Rev. Lett. 122, 130404] Published Tue Apr 02, 2019 - All Sets of Incompatible Measurements give an Advantage in Quantum State Discrimination by Paul Skrzypczyk, Ivan Šupić, and Daniel Cavalcanti (2019/04/02 12:00)Author(s): Paul Skrzypczyk, Ivan Šupić, and Daniel Cavalcanti
Some quantum measurements cannot be performed simultaneously; i.e., they are incompatible. Here we show that every set of incompatible measurements provides an advantage over compatible ones in a suitably chosen quantum state discrimination task. This is proven by showing that the robustness of inco...

[Phys. Rev. Lett. 122, 130403] Published Tue Apr 02, 2019 - Characterizing Multipartite Entanglement with Moments of Random Correlations by Andreas Ketterer, Nikolai Wyderka, and Otfried Gühne (2019/03/29 11:00)Author(s): Andreas Ketterer, Nikolai Wyderka, and Otfried Gühne
The experimental detection of multipartite entanglement usually requires a number of appropriately chosen local quantum measurements that are aligned with respect to a previously shared common reference frame. The latter, however, can be a challenging prerequisite, e.g., for satellite-based photonic...

[Phys. Rev. Lett. 122, 120505] Published Fri Mar 29, 2019 - Stabilizing Arrays of Photonic Cat States via Spontaneous Symmetry Breaking by José Lebreuilly, Camille Aron, and Christophe Mora (2019/03/29 11:00)Author(s): José Lebreuilly, Camille Aron, and Christophe Mora
The controlled generation and the protection of entanglement is key to quantum simulation and quantum computation. At the single-mode level, protocols based on photonic cat states hold strong promise as they present unprecedentedly long-lived coherence and may be combined with powerful error correct...

[Phys. Rev. Lett. 122, 120402] Published Fri Mar 29, 2019 - Quantum Control and Sensing of Nuclear Spins by Electron Spins under Power Limitations by Nati Aharon, Ilai Schwartz, and Alex Retzker (2019/03/29 11:00)Author(s): Nati Aharon, Ilai Schwartz, and Alex Retzker
State of the art quantum sensing experiments targeting frequency measurements or frequency addressing of nuclear spins require one to drive the probe system at the targeted frequency. In addition, there is a substantial advantage to performing these experiments in the regime of high magnetic fields,...

[Phys. Rev. Lett. 122, 120403] Published Fri Mar 29, 2019 - Resource Theory of Entanglement with a Unique Multipartite Maximally Entangled State by Patricia Contreras-Tejada, Carlos Palazuelos, and Julio I. de Vicente (2019/03/28 11:00)Author(s): Patricia Contreras-Tejada, Carlos Palazuelos, and Julio I. de Vicente
Entanglement theory is formulated as a quantum resource theory in which the free operations are local operations and classical communication (LOCC). This defines a partial order among bipartite pure states that makes it possible to identify a maximally entangled state, which turns out to be the most...

[Phys. Rev. Lett. 122, 120503] Published Thu Mar 28, 2019 - Experimental Quantum Switching for Exponentially Superior Quantum Communication Complexity by Kejin Wei, Nora Tischler, Si-Ran Zhao, Yu-Huai Li, Juan Miguel Arrazola, Yang Liu, Weijun Zhang, Hao Li, Lixing You, Zhen Wang, Yu-Ao Chen, Barry C. Sanders, Qiang Zhang, Geoff J. Pryde, Feihu Xu, and Jian-Wei Pan (2019/03/28 11:00)Author(s): Kejin Wei, Nora Tischler, Si-Ran Zhao, Yu-Huai Li, Juan Miguel Arrazola, Yang Liu, Weijun Zhang, Hao Li, Lixing You, Zhen Wang, Yu-Ao Chen, Barry C. Sanders, Qiang Zhang, Geoff J. Pryde, Feihu Xu, and Jian-Wei Pan
Finding exponential separation between quantum and classical information tasks is like striking gold in quantum information research. Such an advantage is believed to hold for quantum computing but is proven for quantum communication complexity. Recently, a novel quantum resource called the quantum ...

[Phys. Rev. Lett. 122, 120504] Published Thu Mar 28, 2019 - Full Counting Statistics and Large Deviations in a Thermal 1D Bose Gas by Maksims Arzamasovs and Dimitri M. Gangardt (2019/03/27 11:00)Author(s): Maksims Arzamasovs and Dimitri M. Gangardt
We obtain the distribution of a number of atoms in an interval (full counting statistics) for interacting bosons in one dimension. Our results are valid in the weakly interacting regime in a parametrically large window of temperatures and interval lengths. The obtained distribution significantly dev...

[Phys. Rev. Lett. 122, 120401] Published Wed Mar 27, 2019 - Universal $N$-Partite $d$-Level Pure-State Entanglement Witness Based on Realistic Measurement Settings by Stefania Sciara, Christian Reimer, Michael Kues, Piotr Roztocki, Alfonso Cino, David J. Moss, Lucia Caspani, William J. Munro, and Roberto Morandotti (2019/03/27 11:00)Author(s): Stefania Sciara, Christian Reimer, Michael Kues, Piotr Roztocki, Alfonso Cino, David J. Moss, Lucia Caspani, William J. Munro, and Roberto Morandotti
Entanglement witnesses are operators that are crucial for confirming the generation of specific quantum systems, such as multipartite and high-dimensional states. For this reason, many witnesses have been theoretically derived which commonly focus on establishing tight bounds and exhibit mathematica...

[Phys. Rev. Lett. 122, 120501] Published Wed Mar 27, 2019 - Scale-Invariant Continuous Entanglement Renormalization of a Chern Insulator by Su-Kuan Chu, Guanyu Zhu, James R. Garrison, Zachary Eldredge, Ana Valdés Curiel, Przemyslaw Bienias, I. B. Spielman, and Alexey V. Gorshkov (2019/03/27 11:00)Author(s): Su-Kuan Chu, Guanyu Zhu, James R. Garrison, Zachary Eldredge, Ana Valdés Curiel, Przemyslaw Bienias, I. B. Spielman, and Alexey V. Gorshkov
The multiscale entanglement renormalization ansatz (MERA) postulates the existence of quantum circuits that renormalize entanglement in real space at different length scales. Chern insulators, however, cannot have scale-invariant discrete MERA circuits with a finite bond dimension. In this Letter, w...

[Phys. Rev. Lett. 122, 120502] Published Wed Mar 27, 2019 - Maximum Entropy Principle in Statistical Inference: Case for Non-Shannonian Entropies by Petr Jizba and Jan Korbel (2019/03/26 11:00)Author(s): Petr Jizba and Jan Korbel
In this Letter, we show that the Shore-Johnson axioms for the maximum entropy principle in statistical estimation theory account for a considerably wider class of entropic functional than previously thought. Apart from a formal side of the proof where a one-parameter class of admissible entropies is...

[Phys. Rev. Lett. 122, 120601] Published Tue Mar 26, 2019 - Avoiding Irreversibility: Engineering Resonant Conversions of Quantum Resources by Kamil Korzekwa, Christopher T. Chubb, and Marco Tomamichel (2019/03/22 11:00)Author(s): Kamil Korzekwa, Christopher T. Chubb, and Marco Tomamichel
We identify and explore the intriguing property of resource resonance arising within resource theories of entanglement, coherence, and thermodynamics. While the theories considered are reversible asymptotically, the same is generally not true in realistic scenarios where the available resources are ...

[Phys. Rev. Lett. 122, 110403] Published Fri Mar 22, 2019 - Absence of Criticality in the Phase Transitions of Open Floquet Systems by Steven Mathey and Sebastian Diehl (2019/03/22 11:00)Author(s): Steven Mathey and Sebastian Diehl
We address the nature of phase transitions in periodically driven systems coupled to a bath. The latter enables a synchronized nonequilibrium Floquet steady state at finite entropy, which we analyze for rapid drives within a nonequilibrium renormalization group (RG) approach. While the infinitely ra...

[Phys. Rev. Lett. 122, 110602] Published Fri Mar 22, 2019 - Pulsed Quantum-State Reconstruction of Dark Systems by Yu Liu, Jiazhao Tian, Ralf Betzholz, and Jianming Cai (2019/03/21 11:00)Author(s): Yu Liu, Jiazhao Tian, Ralf Betzholz, and Jianming Cai
We propose a novel strategy to reconstruct the quantum state of dark systems, i.e., degrees of freedom that are not directly accessible for measurement or control. Our scheme relies on the quantum control of a two-level probe that exerts a state-dependent potential on the dark system. Using a sequen...

[Phys. Rev. Lett. 122, 110406] Published Thu Mar 21, 2019 - Quantum Critical Regime in a Quadratically Driven Nonlinear Photonic Lattice by Riccardo Rota, Fabrizio Minganti, Cristiano Ciuti, and Vincenzo Savona (2019/03/21 11:00)Author(s): Riccardo Rota, Fabrizio Minganti, Cristiano Ciuti, and Vincenzo Savona
We study an array of coupled optical cavities in the presence of two-photon driving and dissipation. The system displays a critical behavior similar to that of a quantum Ising model at finite temperature. Using the corner-space renormalization method, we compute the steady-state properties of finite...

[Phys. Rev. Lett. 122, 110405] Published Thu Mar 21, 2019 - Matter-Wave Diffraction from a Quasicrystalline Optical Lattice by Konrad Viebahn, Matteo Sbroscia, Edward Carter, Jr-Chiun Yu, and Ulrich Schneider (2019/03/20 11:00)Author(s): Konrad Viebahn, Matteo Sbroscia, Edward Carter, Jr-Chiun Yu, and Ulrich Schneider
Experimentalists realize a Bose-Einstein condensate on a 2D quasicrystal optical lattice, opening the path for simulations of a variety of quantum many-body phenomena in these fractal structures.

[Phys. Rev. Lett. 122, 110404] Published Wed Mar 20, 2019 - Ground-State Phase Diagram of a Spin-Orbital-Angular-Momentum Coupled Bose-Einstein Condensate by Dongfang Zhang, Tianyou Gao, Peng Zou, Lingran Kong, Ruizong Li, Xing Shen, Xiao-Long Chen, Shi-Guo Peng, Mingsheng Zhan, Han Pu, and Kaijun Jiang (2019/03/20 11:00)Author(s): Dongfang Zhang, Tianyou Gao, Peng Zou, Lingran Kong, Ruizong Li, Xing Shen, Xiao-Long Chen, Shi-Guo Peng, Mingsheng Zhan, Han Pu, and Kaijun Jiang
By inducing a Raman transition using a pair of Gaussian and Laguerre-Gaussian laser beams, we realize a $^{87}\mathrm{Rb}$ condensate whose orbital angular momentum (OAM) and its internal spin states are coupled. By varying the detuning and the coupling strength of the Raman transition, we experimen...

[Phys. Rev. Lett. 122, 110402] Published Wed Mar 20, 2019 - Genuine 12-Qubit Entanglement on a Superconducting Quantum Processor by Ming Gong, Ming-Cheng Chen, Yarui Zheng, Shiyu Wang, Chen Zha, Hui Deng, Zhiguang Yan, Hao Rong, Yulin Wu, Shaowei Li, Fusheng Chen, Youwei Zhao, Futian Liang, Jin Lin, Yu Xu, Cheng Guo, Lihua Sun, Anthony D. Castellano, Haohua Wang, Chengzhi Peng, Chao-Yang Lu, Xiaobo Zhu, and Jian-Wei Pan (2019/03/20 11:00)Author(s): Ming Gong, Ming-Cheng Chen, Yarui Zheng, Shiyu Wang, Chen Zha, Hui Deng, Zhiguang Yan, Hao Rong, Yulin Wu, Shaowei Li, Fusheng Chen, Youwei Zhao, Futian Liang, Jin Lin, Yu Xu, Cheng Guo, Lihua Sun, Anthony D. Castellano, Haohua Wang, Chengzhi Peng, Chao-Yang Lu, Xiaobo Zhu, and Jian-Wei Pan
Twelve superconducting qubits are entangled, forming a linear cluster state, by using a carefully calibrated sequence of single and 2-qubit quantum gates.

[Phys. Rev. Lett. 122, 110501] Published Wed Mar 20, 2019 - Experimental Demonstration of Quantum Effects in the Operation of Microscopic Heat Engines by James Klatzow, Jonas N. Becker, Patrick M. Ledingham, Christian Weinzetl, Krzysztof T. Kaczmarek, Dylan J. Saunders, Joshua Nunn, Ian A. Walmsley, Raam Uzdin, and Eilon Poem (2019/03/20 11:00)Author(s): James Klatzow, Jonas N. Becker, Patrick M. Ledingham, Christian Weinzetl, Krzysztof T. Kaczmarek, Dylan J. Saunders, Joshua Nunn, Ian A. Walmsley, Raam Uzdin, and Eilon Poem
Experiments demonstrate a quantum-coherence-induced power increase for quantum heat engines over their classical counterparts.

[Phys. Rev. Lett. 122, 110601] Published Wed Mar 20, 2019 - Certifying Nonclassical Behavior for Negative Keldysh Quasiprobabilities by Patrick P. Potts (2019/03/18 11:00)Author(s): Patrick P. Potts
We introduce an experimental test for ruling out classical explanations for the statistics obtained when measuring arbitrary observables at arbitrary times using individual detectors. This test requires some trust in the measurements, represented by a few natural assumptions on the detectors. In qua...

[Phys. Rev. Lett. 122, 110401] Published Mon Mar 18, 2019 - Adaptive Compressive Tomography with No <i>a priori</i> Information by D. Ahn, Y. S. Teo, H. Jeong, F. Bouchard, F. Hufnagel, E. Karimi, D. Koutný, J. Řeháček, Z. Hradil, G. Leuchs, and L. L. Sánchez-Soto (2019/03/15 11:00)Author(s): D. Ahn, Y. S. Teo, H. Jeong, F. Bouchard, F. Hufnagel, E. Karimi, D. Koutný, J. Řeháček, Z. Hradil, G. Leuchs, and L. L. Sánchez-Soto
Quantum state tomography is both a crucial component in the field of quantum information and computation and a formidable task that requires an incogitable number of measurement configurations as the system dimension grows. We propose and experimentally carry out an intuitive adaptive compressive to...

[Phys. Rev. Lett. 122, 100404] Published Fri Mar 15, 2019 - Measurements of Nonlocal Variables and Demonstration of the Failure of the Product Rule for a Pre- and Postselected Pair of Photons by Xiao-Ye Xu, Wei-Wei Pan, Qin-Qin Wang, Jan Dziewior, Lukas Knips, Yaron Kedem, Kai Sun, Jin-Shi Xu, Yong-Jian Han, Chuan-Feng Li, Guang-Can Guo, and Lev Vaidman (2019/03/15 11:00)Author(s): Xiao-Ye Xu, Wei-Wei Pan, Qin-Qin Wang, Jan Dziewior, Lukas Knips, Yaron Kedem, Kai Sun, Jin-Shi Xu, Yong-Jian Han, Chuan-Feng Li, Guang-Can Guo, and Lev Vaidman
We report the first implementation of the von Neumann instantaneous measurements of nonlocal variables, which becomes possible due to technological achievements in creating hyperentangled photons. Tests of reliability and of the nondemolition property of the measurements have been performed with hig...

[Phys. Rev. Lett. 122, 100405] Published Fri Mar 15, 2019 - Elastic Scattering Time of Matter Waves in Disordered Potentials by Jérémie Richard, Lih-King Lim, Vincent Denechaud, Valentin V. Volchkov, Baptiste Lecoutre, Musawwadah Mukhtar, Fred Jendrzejewski, Alain Aspect, Adrien Signoles, Laurent Sanchez-Palencia, and Vincent Josse (2019/03/13 11:00)Author(s): Jérémie Richard, Lih-King Lim, Vincent Denechaud, Valentin V. Volchkov, Baptiste Lecoutre, Musawwadah Mukhtar, Fred Jendrzejewski, Alain Aspect, Adrien Signoles, Laurent Sanchez-Palencia, and Vincent Josse
We report on an extensive study of the elastic scattering time ${τ}_{s}$ of matter waves in optical disordered potentials. Using direct experimental measurements, numerical simulations, and comparison with the first-order Born approximation based on the knowledge of the disorder properties, we explo...

[Phys. Rev. Lett. 122, 100403] Published Wed Mar 13, 2019 - Nanoscale Vector dc Magnetometry via Ancilla-Assisted Frequency Up-Conversion by Yi-Xiang Liu (刘仪襄), Ashok Ajoy, and Paola Cappellaro (2019/03/13 11:00)Author(s): Yi-Xiang Liu (刘仪襄), Ashok Ajoy, and Paola Cappellaro
Sensing static magnetic fields with high sensitivity and spatial resolution is critical to many applications in fundamental physics, bioimaging, and materials science. Even more beneficial would be full vector magnetometry with nanoscale spatial resolution. Several versatile magnetometry platforms h...

[Phys. Rev. Lett. 122, 100501] Published Wed Mar 13, 2019

##### Physical Review E

- Inhibition-induced explosive synchronization in multiplex networks by Sarika Jalan, Vasundhara Rathore, Ajay Deep Kachhvah, and Alok Yadav (2019/06/14 12:00)Author(s): Sarika Jalan, Vasundhara Rathore, Ajay Deep Kachhvah, and Alok Yadav
To date, explosive synchronization (ES) in a network is shown to be originated from considering either degree-frequency correlation, frequency-coupling strength correlation, inertia, or adaptively controlled phase oscillators. Here we show that ES is a generic phenomenon and can occur in any network...

[Phys. Rev. E 99, 062305] Published Fri Jun 14, 2019 - Random walker's view of networks whose growth it shapes by Robert J. H. Ross, Charlotte Strandkvist, and Walter Fontana (2019/06/14 12:00)Author(s): Robert J. H. Ross, Charlotte Strandkvist, and Walter Fontana
We study a simple model in which the growth of a network is determined by the location of one or more random walkers. Depending on walker motility rate, the model generates a spectrum of structures situated between well-known limiting cases. We demonstrate that the average degree observed by a walke...

[Phys. Rev. E 99, 062306] Published Fri Jun 14, 2019 - Neural field theory of evoked response potentials in a spherical brain geometry by K. N. Mukta, Xiao Gao, and P. A. Robinson (2019/06/12 12:00)Author(s): K. N. Mukta, Xiao Gao, and P. A. Robinson
Evoked response potentials (ERPs) are calculated in spherical and planar geometries using neural field theory of the corticothalamic system. The ERP is modeled as an impulse response and the resulting modal effects of spherical corticothalamic dynamics are explored, showing that results for spherica...

[Phys. Rev. E 99, 062304] Published Wed Jun 12, 2019 - Turing patterns mediated by network topology in homogeneous active systems by Sayat Mimar, Mariamo Mussa Juane, Juyong Park, Alberto P. Muñuzuri, and Gourab Ghoshal (2019/06/11 12:00)Author(s): Sayat Mimar, Mariamo Mussa Juane, Juyong Park, Alberto P. Muñuzuri, and Gourab Ghoshal
Mechanisms of pattern formation—of which the Turing instability is an archetype—constitute an important class of dynamical processes occurring in biological, ecological, and chemical systems. Recently, it has been shown that the Turing instability can induce pattern formation in discrete media such ...

[Phys. Rev. E 99, 062303] Published Tue Jun 11, 2019 - Mean-field solution of structural balance dynamics in nonzero temperature by F. Rabbani, Amir H. Shirazi, and G. R. Jafari (2019/06/10 12:00)Author(s): F. Rabbani, Amir H. Shirazi, and G. R. Jafari
In signed networks with simultaneous friendly and hostile interactions, there is a general tendency to a global structural balance, based on the dynamical model of links status. Although the structural balance represents a state of the network with a lack of contentious situations, there are always ...

[Phys. Rev. E 99, 062302] Published Mon Jun 10, 2019 - Social clustering in epidemic spread on coevolving networks by Hsuan-Wei Lee, Nishant Malik, Feng Shi, and Peter J. Mucha (2019/06/04 12:00)Author(s): Hsuan-Wei Lee, Nishant Malik, Feng Shi, and Peter J. Mucha
Even though transitivity is a central structural feature of social networks, its influence on epidemic spread on coevolving networks has remained relatively unexplored. Here we introduce and study an adaptive susceptible-infected-susceptible (SIS) epidemic model wherein the infection and network coe...

[Phys. Rev. E 99, 062301] Published Tue Jun 04, 2019 - Fault tolerance of random graphs with respect to connectivity: Mean-field approximation for semidense random graphs by Satoshi Takabe, Takafumi Nakano, and Tadashi Wadayama (2019/05/29 12:00)Author(s): Satoshi Takabe, Takafumi Nakano, and Tadashi Wadayama
The fault tolerance of random graphs with unbounded degrees with respect to connectivity is investigated, which relates to the reliability of wireless sensor networks with unreliable relay nodes. The model evaluates the network breakdown probability that a graph is disconnected after stochastic node...

[Phys. Rev. E 99, 050304(R)] Published Wed May 29, 2019 - Individual perception dynamics in drunk games by Alberto Antonioni, Luis A. Martinez-Vaquero, Cole Mathis, Leto Peel, and Massimo Stella (2019/05/28 12:00)Author(s): Alberto Antonioni, Luis A. Martinez-Vaquero, Cole Mathis, Leto Peel, and Massimo Stella
We study the effects of individual perceptions of payoffs in two-player games. In particular we consider the setting in which individuals' perceptions of the game are influenced by their previous experiences and outcomes. Accordingly, we introduce a framework based on evolutionary games where indivi...

[Phys. Rev. E 99, 052311] Published Tue May 28, 2019 - Expanding spatial domains and transient scaling regimes in populations with local cyclic competition by P. P. Avelino, J. Menezes, B. F. de Oliveira, and T. A. Pereira (2019/05/24 12:00)Author(s): P. P. Avelino, J. Menezes, B. F. de Oliveira, and T. A. Pereira
We investigate a six-species class of May-Leonard models leading to the formation of two types of competing spatial domains, each one inhabited by three species with their own internal cyclic rock-paper-scissors dynamics. We study the resulting population dynamics using stochastic numerical simulati...

[Phys. Rev. E 99, 052310] Published Fri May 24, 2019 - Spreading of computer viruses on time-varying networks by Terry Brett, George Loukas, Yamir Moreno, and Nicola Perra (2019/05/24 12:00)Author(s): Terry Brett, George Loukas, Yamir Moreno, and Nicola Perra
Social networks are the prime channel for the spreading of computer viruses. Yet the study of their propagation neglects the temporal nature of social interactions and the heterogeneity of users' susceptibility. Here, we introduce a theoretical framework that captures both properties. We study two r...

[Phys. Rev. E 99, 050303(R)] Published Fri May 24, 2019 - Order parameter allows classification of planar graphs based on balanced fixed points in the Kuramoto model by Franz Kaiser and Karen Alim (2019/05/23 12:00)Author(s): Franz Kaiser and Karen Alim
Phase

*balanced states*are a highly underexplored class of solutions of the Kuramoto model and other coupled oscillator models on networks. So far, coupled oscillator research focused on phase synchronized solutions. Yet, global constraints on oscillators may forbid synchronized state, rendering phas...

[Phys. Rev. E 99, 052308] Published Thu May 23, 2019 - Graph comparison via the nonbacktracking spectrum by Andrew Mellor and Angelica Grusovin (2019/05/23 12:00)Author(s): Andrew Mellor and Angelica Grusovin
The comparison of graphs is a vitally important, yet difficult task which arises across a number of diverse research areas including biological and social networks. There have been a number of approaches to define graph distance, however, often these are not metrics (rendering standard data-mining t...

[Phys. Rev. E 99, 052309] Published Thu May 23, 2019 - Voter model on networks and the multivariate beta distribution by Shintaro Mori, Masato Hisakado, and Kazuaki Nakayama (2019/05/22 12:00)Author(s): Shintaro Mori, Masato Hisakado, and Kazuaki Nakayama
In elections, the vote shares or turnout rates show a strong spatial correlation. The logarithmic decay with distance suggests that a two-dimensional (2D) noisy diffusive equation describes the system. Based on the study of U.S. presidential elections data, it was determined that the fluctuations of...

[Phys. Rev. E 99, 052307] Published Wed May 22, 2019 - Energy cost for controlling complex networks with linear dynamics by Gaopeng Duan, Aming Li, Tao Meng, Guofeng Zhang, and Long Wang (2019/05/21 12:00)Author(s): Gaopeng Duan, Aming Li, Tao Meng, Guofeng Zhang, and Long Wang
Examining the controllability of complex networks has received much attention recently. The focus of many studies is commonly trained on whether we can steer a system from an arbitrary initial state to any final state within finite time with admissible external inputs. In order to accomplish the con...

[Phys. Rev. E 99, 052305] Published Tue May 21, 2019 - Emergence of frustration signals systemic risk by Chandrashekar Kuyyamudi, Anindya S. Chakrabarti, and Sitabhra Sinha (2019/05/21 12:00)Author(s): Chandrashekar Kuyyamudi, Anindya S. Chakrabarti, and Sitabhra Sinha
We show that the emergence of systemic risk in complex systems can be understood from the evolution of functional networks representing interactions inferred from fluctuation correlations between macroscopic observables. Specifically, we analyze the long-term collective dynamics in the New York Stoc...

[Phys. Rev. E 99, 052306] Published Tue May 21, 2019 - Propagation of wind-power-induced fluctuations in power grids by Hauke Haehne, Katrin Schmietendorf, Samyak Tamrakar, Joachim Peinke, and Stefan Kettemann (2019/05/20 12:00)Author(s): Hauke Haehne, Katrin Schmietendorf, Samyak Tamrakar, Joachim Peinke, and Stefan Kettemann
Renewable generators perturb the electric power grid with heavily non-Gaussian and time correlated fluctuations. While changes in generated power on timescales of minutes and hours are compensated by frequency control measures, we report subsecond distribution grid frequency measurements with local ...

[Phys. Rev. E 99, 050301(R)] Published Mon May 20, 2019 - Sampling networks by nodal attributes by Yohsuke Murase, Hang-Hyun Jo, János Török, János Kertész, and Kimmo Kaski (2019/05/15 12:00)Author(s): Yohsuke Murase, Hang-Hyun Jo, János Török, János Kertész, and Kimmo Kaski
In a social network individuals or nodes connect to other nodes by choosing one of the channels of communication at a time to re-establish the existing social links. Since available data sets are usually restricted to a limited number of channels or layers, these autonomous decision making processes...

[Phys. Rev. E 99, 052304] Published Wed May 15, 2019 - Optimal geometry of transportation networks by David Aldous and Marc Barthelemy (2019/05/14 12:00)Author(s): David Aldous and Marc Barthelemy
Motivated by the shape of transportation networks such as subways, we consider a distribution of points in the plane and ask for the network $G$ of given length $L$ that is optimal in a certain sense. In the general model, the optimality criterion is to minimize the average (over pairs of points cho...

[Phys. Rev. E 99, 052303] Published Tue May 14, 2019 - Impact of perception models on friendship paradox and opinion formation by Eun Lee, Sungmin Lee, Young-Ho Eom, Petter Holme, and Hang-Hyun Jo (2019/05/10 12:00)Author(s): Eun Lee, Sungmin Lee, Young-Ho Eom, Petter Holme, and Hang-Hyun Jo
Topological heterogeneities of social networks have a strong impact on the individuals embedded in those networks. One of the interesting phenomena driven by such heterogeneities is the friendship paradox (FP), stating that the mean degree of one's neighbors is larger than the degree of oneself. Alt...

[Phys. Rev. E 99, 052302] Published Fri May 10, 2019 - Fading of remote synchronization in tree networks of Stuart-Landau oscillators by Baris Karakaya, Ludovico Minati, Lucia Valentina Gambuzza, and Mattia Frasca (2019/05/01 12:00)Author(s): Baris Karakaya, Ludovico Minati, Lucia Valentina Gambuzza, and Mattia Frasca
Remote synchronization (RS) is characterized by the appearance of phase coherence between oscillators that do not directly interact through a structural link in a network but exclusively through other units that are not synchronized or more weakly synchronized with them. This form of phase synchroni...

[Phys. Rev. E 99, 052301] Published Wed May 01, 2019 - Reconstruction of dynamic networks with time-delayed interactions in the presence of fast-varying noises by Zhaoyang Zhang, Yang Chen, Yuanyuan Mi, and Gang Hu (2019/04/30 12:00)Author(s): Zhaoyang Zhang, Yang Chen, Yuanyuan Mi, and Gang Hu
Most complex social, biological and technological systems can be described by dynamic networks. Reconstructing network structures from measurable data is a fundamental problem in almost all interdisciplinary fields. Network nodes interact with each other and those interactions often have diversely d...

[Phys. Rev. E 99, 042311] Published Tue Apr 30, 2019 - Detectability of macroscopic structures in directed asymmetric stochastic block model by Mateusz Wilinski, Piero Mazzarisi, Daniele Tantari, and Fabrizio Lillo (2019/04/23 12:00)Author(s): Mateusz Wilinski, Piero Mazzarisi, Daniele Tantari, and Fabrizio Lillo
We study the problem of identifying macroscopic structures in networks, characterizing the impact of introducing link directions on the detectability phase transition. To this end, building on the stochastic block model, we construct a class of nontrivially detectable directed networks. We find clos...

[Phys. Rev. E 99, 042310] Published Tue Apr 23, 2019 - Spectra of random networks with arbitrary degrees by M. E. J. Newman, Xiao Zhang, and Raj Rao Nadakuditi (2019/04/18 12:00)Author(s): M. E. J. Newman, Xiao Zhang, and Raj Rao Nadakuditi
We derive a message-passing method for computing the spectra of locally treelike networks and an approximation to it that allows us to compute closed-form expressions or fast numerical approximates for the spectral density of random graphs with arbitrary node degrees—the so-called configuration mode...

[Phys. Rev. E 99, 042309] Published Thu Apr 18, 2019 - Diffusion dynamics of a conductance-based neuronal population by Argha Mondal, Sanjeev Kumar Sharma, Ranjit Kumar Upadhyay, M. A. Aziz-Alaoui, Prosenjit Kundu, and Chittaranjan Hens (2019/04/17 12:00)Author(s): Argha Mondal, Sanjeev Kumar Sharma, Ranjit Kumar Upadhyay, M. A. Aziz-Alaoui, Prosenjit Kundu, and Chittaranjan Hens
We study the spatiotemporal dynamics of a conductance-based neuronal cable. The processes of one-dimensional (1D) and 2D diffusion are considered for a single variable, which is the membrane voltage. A 2D Morris-Lecar (ML) model is introduced to investigate the nonlinear responses of an excitable co...

[Phys. Rev. E 99, 042307] Published Wed Apr 17, 2019 - Generating random networks that consist of a single connected component with a given degree distribution by Ido Tishby, Ofer Biham, Eytan Katzav, and Reimer Kühn (2019/04/17 12:00)Author(s): Ido Tishby, Ofer Biham, Eytan Katzav, and Reimer Kühn
We present a method for the construction of ensembles of random networks that consist of a single connected component with a given degree distribution. This approach extends the construction toolbox of random networks beyond the configuration model framework, in which one controls the degree distrib...

[Phys. Rev. E 99, 042308] Published Wed Apr 17, 2019 - Enhancing network synchronizability by strengthening a single node by Huawei Fan, Yafeng Wang, Kai Yang, and Xingang Wang (2019/04/16 12:00)Author(s): Huawei Fan, Yafeng Wang, Kai Yang, and Xingang Wang
In improving the stability of complex dynamical systems, an outstanding problem is how to achieve the desired performance at a low cost. For engineering and biological complex systems whose performance and functionality rely on the synchronous motion of their units, an important question related to ...

[Phys. Rev. E 99, 042305] Published Tue Apr 16, 2019 - Mixing patterns and individual differences in networks by George T. Cantwell and M. E. J. Newman (2019/04/16 12:00)Author(s): George T. Cantwell and M. E. J. Newman
We study mixing patterns in networks, meaning the propensity for nodes of different kinds to connect to one another. The phenomenon of assortative mixing, whereby nodes prefer to connect to others that are similar to themselves, has been widely studied, but here we go further and examine how and to ...

[Phys. Rev. E 99, 042306] Published Tue Apr 16, 2019 - Fixation time in evolutionary graphs: A mean-field approach by Mahdi Hajihashemi and Keivan Aghababaei Samani (2019/04/12 12:00)Author(s): Mahdi Hajihashemi and Keivan Aghababaei Samani
Using an analytical method we calculate average conditional fixation time of mutants in a general graph-structured population of two types of species. The method is based on Markov chains and uses a mean-field approximation to calculate the corresponding transition matrix. Analytical results are com...

[Phys. Rev. E 99, 042304] Published Fri Apr 12, 2019 - Multifractality in random networks with power-law decaying bond strengths by Didier A. Vega-Oliveros, J. A. Méndez-Bermúdez, and Francisco A. Rodrigues (2019/04/10 12:00)Author(s): Didier A. Vega-Oliveros, J. A. Méndez-Bermúdez, and Francisco A. Rodrigues
In this paper we demonstrate numerically that random networks whose adjacency matrices $\mathbf{A}$ are represented by a diluted version of the power-law banded random matrix (PBRM) model have multifractal eigenfunctions. The PBRM model describes one-dimensional samples with random long-range bonds....

[Phys. Rev. E 99, 042303] Published Wed Apr 10, 2019 - Fragility and anomalous susceptibility of weakly interacting networks by Giacomo Rapisardi, Alex Arenas, Guido Caldarelli, and Giulio Cimini (2019/04/03 12:00)Author(s): Giacomo Rapisardi, Alex Arenas, Guido Caldarelli, and Giulio Cimini
Percolation is a fundamental concept that has brought new understanding of the robustness properties of complex systems. Here we consider percolation on weakly interacting networks, that is, network layers coupled together by much fewer interlinks than the connections within each layer. For these ki...

[Phys. Rev. E 99, 042302] Published Wed Apr 03, 2019 - Critical transitions in heterogeneous networks: Loss of low-degree nodes as an early warning signal by Alessandro Loppini, Simonetta Filippi, and H. Eugene Stanley (2019/04/02 12:00)Author(s): Alessandro Loppini, Simonetta Filippi, and H. Eugene Stanley
A large number of real networks show abrupt phase transition phenomena in response to environmental changes. In this case, cascading phenomena can induce drastic and discontinuous changes in the system state and lead to collapse. Although complex network theory has been used to investigate these dra...

[Phys. Rev. E 99, 040301(R)] Published Tue Apr 02, 2019 - Fast consensus clustering in complex networks by Aditya Tandon, Aiiad Albeshri, Vijey Thayananthan, Wadee Alhalabi, and Santo Fortunato (2019/04/01 12:00)Author(s): Aditya Tandon, Aiiad Albeshri, Vijey Thayananthan, Wadee Alhalabi, and Santo Fortunato
Algorithms for community detection are usually stochastic, leading to different partitions for different choices of random seeds. Consensus clustering has proven to be an effective technique to derive more stable and accurate partitions than the ones obtained by the direct application of the algorit...

[Phys. Rev. E 99, 042301] Published Mon Apr 01, 2019 - Understanding the temporal pattern of spreading in heterogeneous networks: Theory of the mean infection time by Mi Jin Lee and Deok-Sun Lee (2019/03/29 11:00)Author(s): Mi Jin Lee and Deok-Sun Lee
For a reliable prediction of an epidemic or information spreading pattern in complex systems, well-defined measures are essential. In the susceptible-infected model on heterogeneous networks, the cluster of infected nodes in the intermediate-time regime exhibits too large fluctuation in size to use ...

[Phys. Rev. E 99, 032309] Published Fri Mar 29, 2019 - Network model of conviction-driven social segregation by Gianluca Teza, Samir Suweis, Marco Gherardi, Amos Maritan, and Marco Cosentino Lagomarsino (2019/03/29 11:00)Author(s): Gianluca Teza, Samir Suweis, Marco Gherardi, Amos Maritan, and Marco Cosentino Lagomarsino
To measure, predict, and prevent social segregation, it is necessary to understand the factors that cause it. While in most available descriptions space plays an essential role, one outstanding question is whether and how this phenomenon is possible in a well-mixed social network. We define and solv...

[Phys. Rev. E 99, 032310] Published Fri Mar 29, 2019 - Cascading failures in scale-free interdependent networks by Malgorzata Turalska, Keith Burghardt, Martin Rohden, Ananthram Swami, and Raissa M. D'Souza (2019/03/28 11:00)Author(s): Malgorzata Turalska, Keith Burghardt, Martin Rohden, Ananthram Swami, and Raissa M. D'Souza
Large cascades are a common occurrence in many natural and engineered complex systems. In this paper we explore the propagation of cascades across networks using realistic network topologies, such as heterogeneous degree distributions, as well as intra- and interlayer degree correlations. We find th...

[Phys. Rev. E 99, 032308] Published Thu Mar 28, 2019 - Dynamics of multiplayer games on complex networks using territorial interactions by Pedro H. T. Schimit, Karan Pattni, and Mark Broom (2019/03/27 11:00)Author(s): Pedro H. T. Schimit, Karan Pattni, and Mark Broom
The modeling of evolution in structured populations has been significantly advanced by evolutionary graph theory, which incorporates pairwise relationships between individuals on a network. More recently, a new framework has been developed to allow for multiplayer interactions of variable size in mo...

[Phys. Rev. E 99, 032306] Published Wed Mar 27, 2019 - Tensorial and bipartite block models for link prediction in layered networks and temporal networks by Marc Tarrés-Deulofeu, Antonia Godoy-Lorite, Roger Guimerà, and Marta Sales-Pardo (2019/03/27 11:00)Author(s): Marc Tarrés-Deulofeu, Antonia Godoy-Lorite, Roger Guimerà, and Marta Sales-Pardo
Many real-world complex systems are well represented as multilayer networks; predicting interactions in those systems is one of the most pressing problems in predictive network science. To address this challenge, we introduce two stochastic block models for multilayer and temporal networks; one of t...

[Phys. Rev. E 99, 032307] Published Wed Mar 27, 2019 - Statistical physics of language maps in the USA by J. Burridge, B. Vaux, M. Gnacik, and Y. Grudeva (2019/03/14 11:00)Author(s): J. Burridge, B. Vaux, M. Gnacik, and Y. Grudeva
Spatial linguistic surveys often reveal well-defined geographical zones where certain linguistic forms are dominant over their alternatives. It has been suggested that these patterns may be understood by analogy with coarsening in models of two-dimensional physical systems. Here we investigate this ...

[Phys. Rev. E 99, 032305] Published Thu Mar 14, 2019 - Detecting single-cell stimulation in a large network of integrate-and-fire neurons by Davide Bernardi and Benjamin Lindner (2019/03/11 11:00)Author(s): Davide Bernardi and Benjamin Lindner
Several experiments have shown that the stimulation of a single neuron in the cortex can influence the local network activity and even the behavior of an animal. From the theoretical point of view, it is not clear how stimulating a single cell in a cortical network can evoke a statistically signific...

[Phys. Rev. E 99, 032304] Published Mon Mar 11, 2019 - Controlling and enhancing synchronization through adaptive phase lags by Alexander C. Kalloniatis and Markus Brede (2019/03/07 11:00)Author(s): Alexander C. Kalloniatis and Markus Brede
We compare two methods for controlling synchronization in the Kuramoto model on an undirected network. The first is by driving selected oscillators at a desired frequency by coupling to an external driver, and the second is by including adaptive lags—or dynamical frustrations—within the Kuramoto int...

[Phys. Rev. E 99, 032303] Published Thu Mar 07, 2019 - Mobility helps problem-solving systems to avoid groupthink by Paulo F. Gomes, Sandro M. Reia, Francisco A. Rodrigues, and José F. Fontanari (2019/03/06 11:00)Author(s): Paulo F. Gomes, Sandro M. Reia, Francisco A. Rodrigues, and José F. Fontanari
Groupthink occurs when everyone in a group starts thinking alike, as when people put unlimited faith in a leader. Avoiding this phenomenon is a ubiquitous challenge to problem-solving enterprises and typical countermeasures involve the mobility of group members. Here we use an agent-based model of i...

[Phys. Rev. E 99, 032301] Published Wed Mar 06, 2019 - Reinforcement learning meets minority game: Toward optimal resource allocation by Si-Ping Zhang, Jia-Qi Dong, Li Liu, Zi-Gang Huang, Liang Huang, and Ying-Cheng Lai (2019/03/06 11:00)Author(s): Si-Ping Zhang, Jia-Qi Dong, Li Liu, Zi-Gang Huang, Liang Huang, and Ying-Cheng Lai
The main point of this paper is to provide an affirmative answer through exploiting reinforcement learning (RL) in artificial intelligence (AI) for eliminating herding without any external control in complex resource allocation systems. In particular, we demonstrate that when agents are empowered wi...

[Phys. Rev. E 99, 032302] Published Wed Mar 06, 2019 - Grand canonical ensemble of weighted networks by Andrea Gabrielli, Rossana Mastrandrea, Guido Caldarelli, and Giulio Cimini (2019/03/01 11:00)Author(s): Andrea Gabrielli, Rossana Mastrandrea, Guido Caldarelli, and Giulio Cimini
The cornerstone of statistical mechanics of complex networks is the idea that the links, and not the nodes, are the effective particles of the system. Here, we formulate a mapping between weighted networks and lattice gases, making the conceptual step forward of interpreting weighted links as partic...

[Phys. Rev. E 99, 030301(R)] Published Fri Mar 01, 2019 - Hipsters on networks: How a minority group of individuals can lead to an antiestablishment majority by Jonas S. Juul and Mason A. Porter (2019/02/26 11:00)Author(s): Jonas S. Juul and Mason A. Porter
The spread of opinions, memes, diseases, and “alternative facts” in a population depends both on the details of the spreading process and on the structure of the social and communication networks on which they spread. One feature that can change spreading dynamics substantially is heterogeneous beha...

[Phys. Rev. E 99, 022313] Published Tue Feb 26, 2019 - Role of hubs in the synergistic spread of behavior by Yongjoo Baek, Kihong Chung, Meesoon Ha, Hawoong Jeong, and Daniel Kim (2019/02/25 11:00)Author(s): Yongjoo Baek, Kihong Chung, Meesoon Ha, Hawoong Jeong, and Daniel Kim
The spread of behavior in a society has two major features: the synergy of multiple spreaders and the dominance of hubs. While strong synergy is known to induce mixed-order transitions (MOTs) at percolation, the effects of hubs on the phenomena are yet to be clarified. By analytically solving the ge...

[Phys. Rev. E 99, 020301(R)] Published Mon Feb 25, 2019 - Generalization of core percolation on complex networks by N. Azimi-Tafreshi, S. Osat, and S. N. Dorogovtsev (2019/02/22 11:00)Author(s): N. Azimi-Tafreshi, S. Osat, and S. N. Dorogovtsev
We introduce a $k$-leaf removal algorithm as a generalization of the so-called leaf removal algorithm. In this pruning algorithm, vertices of degree smaller than $k$, together with their first nearest neighbors and all incident edges, are progressively removed from a random network. As the result of...

[Phys. Rev. E 99, 022312] Published Fri Feb 22, 2019 - Insights into bootstrap percolation: Its equivalence with k-core percolation and the giant component by Matías A. Di Muro, Lucas D. Valdez, H. Eugene Stanley, Sergey V. Buldyrev, and Lidia A. Braunstein (2019/02/21 11:00)Author(s): Matías A. Di Muro, Lucas D. Valdez, H. Eugene Stanley, Sergey V. Buldyrev, and Lidia A. Braunstein
K-core and bootstrap percolation are widely studied models that have been used to represent and understand diverse deactivation and activation processes in natural and social systems. Since these models are considerably similar, it has been suggested in recent years that they could be complementary....

[Phys. Rev. E 99, 022311] Published Thu Feb 21, 2019 - Minimal sets to destroy the $k$-core in random networks by Christian Schmidt, Henry D. Pfister, and Lenka Zdeborová (2019/02/20 11:00)Author(s): Christian Schmidt, Henry D. Pfister, and Lenka Zdeborová
We study the problem of finding the smallest set of nodes in a network whose removal results in an empty $k$-core, where the $k$-core is the subnetwork obtained after the iterative removal of all nodes of degree smaller than $k$. This problem is also known in the literature as finding the minimal co...

[Phys. Rev. E 99, 022310] Published Wed Feb 20, 2019 - Coevolution of nodes and links: Diversity-driven coexistence in cyclic competition of three species by Kevin E. Bassler, Erwin Frey, and R. K. P. Zia (2019/02/15 11:00)Author(s): Kevin E. Bassler, Erwin Frey, and R. K. P. Zia
When three species compete cyclically in a well-mixed, stochastic system of $N$ individuals, extinction is known to typically occur at times scaling as the system size $N$. This happens, for example, in rock-paper-scissors games or conserved Lotka-Volterra models in which every pair of individuals c...

[Phys. Rev. E 99, 022309] Published Fri Feb 15, 2019 - Persistent spatial patterns of interacting contagions by Li Chen (2019/02/14 11:00)Author(s): Li Chen
The spread of infectious diseases, rumors, fashions, and innovations are complex contagion processes, embedded in network and spatial contexts. While the studies in the former context are intensively expanded, the latter remains largely unexplored. In this paper, we investigate the pattern formation...

[Phys. Rev. E 99, 022308] Published Thu Feb 14, 2019 - Synchronization in network geometries with finite spectral dimension by Ana P. Millán, Joaquín J. Torres, and Ginestra Bianconi (2019/02/12 11:00)Author(s): Ana P. Millán, Joaquín J. Torres, and Ginestra Bianconi
Recently there is a surge of interest in network geometry and topology. Here we show that the spectral dimension plays a fundamental role in establishing a clear relation between the topological and geometrical properties of a network and its dynamics. Specifically we explore the role of the spectra...

[Phys. Rev. E 99, 022307] Published Tue Feb 12, 2019 - Entropy-based randomization of rating networks by Carolina Becatti, Guido Caldarelli, and Fabio Saracco (2019/02/07 11:00)Author(s): Carolina Becatti, Guido Caldarelli, and Fabio Saracco
In recent years, due to the great diffusion of e-commerce, online rating platforms quickly became a common tool for purchase recommendations. However, instruments for their analysis did not evolve at the same speed. Indeed, interesting information about users' habits and tastes can be recovered just...

[Phys. Rev. E 99, 022306] Published Thu Feb 07, 2019 - Population size changes and extinction risk of populations driven by mutant interactors by Hye Jin Park, Yuriy Pichugin, Weini Huang, and Arne Traulsen (2019/02/06 11:00)Author(s): Hye Jin Park, Yuriy Pichugin, Weini Huang, and Arne Traulsen
Spontaneous random mutations are an important source of variation in populations. Many evolutionary models consider mutants with a fixed fitness, chosen from a fitness distribution without considering microscopic interactions among the residents and mutants. Here, we go beyond this and consider “mut...

[Phys. Rev. E 99, 022305] Published Wed Feb 06, 2019 - Percolation framework of the Earth's topography by Jingfang Fan, Jun Meng, and Abbas Ali Saberi (2019/02/05 11:00)Author(s): Jingfang Fan, Jun Meng, and Abbas Ali Saberi
Self-similarity and long-range correlations are the remarkable features of the Earth's surface topography. Here we develop an approach based on percolation theory to study the geometrical features of Earth. Our analysis is based on high-resolution, 1 arc min, ETOPO1 global relief records. We find so...

[Phys. Rev. E 99, 022304] Published Tue Feb 05, 2019 - Similar size of slums caused by a Turing instability of migration behavior by Peter F. Pelz, John Friesen, and Jakob Hartig (2019/02/04 11:00)Author(s): Peter F. Pelz, John Friesen, and Jakob Hartig
It is a remarkable fact that the size of slums is similar across the globe, regardless of city, country, or culture [Friesen

*et al.*, Habitat Int.**73**, 79 (2018)]. The main thesis of this paper is that this universal scale is intrinsic to the slum-city system and is independent from external factors....

[Phys. Rev. E 99, 022302] Published Mon Feb 04, 2019 - Distinct dynamical behavior in Erdős-Rényi networks, regular random networks, ring lattices, and all-to-all neuronal networks by M. A. Lopes and A. V. Goltsev (2019/02/04 11:00)Author(s): M. A. Lopes and A. V. Goltsev
Neuronal network dynamics depends on network structure. In this paper we study how network topology underpins the emergence of different dynamical behaviors in neuronal networks. In particular, we consider neuronal network dynamics on Erdős-Rényi (ER) networks, regular random (RR) networks, ring lat...

[Phys. Rev. E 99, 022303] Published Mon Feb 04, 2019 - Effect of network clustering on mutually cooperative coinfections by Peng-Bi Cui (崔鹏碧), Francesca Colaiori, and Claudio Castellano (2019/02/01 11:00)Author(s): Peng-Bi Cui (崔鹏碧), Francesca Colaiori, and Claudio Castellano
When two cooperative contagious diseases spread, there can be a discontinuous epidemic transition depending on the topology of the network of contacts. The authors’ model shows that increasing the number of local contact clusters decreases the size of the discontinuity, but does not remove it. Due to strong finite size effects the discontinuous nature of the transition is then only visible in large networks

[Phys. Rev. E 99, 022301] Published Fri Feb 01, 2019 - Role of persistent cascades in diffusion by Steven Morse, Marta C. González, and Natasha Markuzon (2019/01/28 11:00)Author(s): Steven Morse, Marta C. González, and Natasha Markuzon
We define a structural property of real-world large-scale communication networks consisting of the recurring patterns of communication among individuals, which we term persistent cascades. Using methods of inexact tree matching and agglomerative clustering, we group these patterns into classes which...

[Phys. Rev. E 99, 012323] Published Mon Jan 28, 2019 - Link persistence and conditional distances in multiplex networks by Fragkiskos Papadopoulos and Kaj-Kolja Kleineberg (2019/01/25 11:00)Author(s): Fragkiskos Papadopoulos and Kaj-Kolja Kleineberg
Recent progress towards unraveling the hidden geometric organization of real multiplexes revealed significant correlations across the hyperbolic node coordinates in different network layers, which facilitated applications like translayer link prediction and mutual navigation. But, are geometric corr...

[Phys. Rev. E 99, 012322] Published Fri Jan 25, 2019 - Resilience in hierarchical fluid flow networks by Tatyana Gavrilchenko and Eleni Katifori (2019/01/25 11:00)Author(s): Tatyana Gavrilchenko and Eleni Katifori
The structure of flow networks determines their function under normal conditions as well as their response to perturbative damage. Brain vasculature often experiences transient or permanent occlusions in the finest vessels, but it is not clear how these microclots affect the large-scale blood flow o...

[Phys. Rev. E 99, 012321] Published Fri Jan 25, 2019 - Pattern recognition with neuronal avalanche dynamics by L. Michiels van Kessenich, D. Berger, L. de Arcangelis, and H. J. Herrmann (2019/01/22 11:00)Author(s): L. Michiels van Kessenich, D. Berger, L. de Arcangelis, and H. J. Herrmann
Pattern recognition is a fundamental neuronal process which enables a cortical system to interpret visual stimuli. How the brain learns to recognize patterns is, however, an unsolved problem. The frequently employed method of back propagation excels at this task but has been found to be unbiological...

[Phys. Rev. E 99, 010302(R)] Published Tue Jan 22, 2019 - Balance in signed networks by Alec Kirkley, George T. Cantwell, and M. E. J. Newman (2019/01/22 11:00)Author(s): Alec Kirkley, George T. Cantwell, and M. E. J. Newman
We consider signed networks in which connections or edges can be either positive (friendship, trust, alliance) or negative (dislike, distrust, conflict). Early literature in graph theory theorized that such networks should display “structural balance,” meaning that certain configurations of positive...

[Phys. Rev. E 99, 012320] Published Tue Jan 22, 2019 - Inferring directed networks using a rank-based connectivity measure by Marc G. Leguia, Cristina G. B. Martínez, Irene Malvestio, Adrià Tauste Campo, Rodrigo Rocamora, Zoran Levnajić, and Ralph G. Andrzejak (2019/01/22 11:00)Author(s): Marc G. Leguia, Cristina G. B. Martínez, Irene Malvestio, Adrià Tauste Campo, Rodrigo Rocamora, Zoran Levnajić, and Ralph G. Andrzejak
Inferring the topology of a network using the knowledge of the signals of each of the interacting units is key to understanding real-world systems. One way to address this problem is using data-driven methods like cross-correlation or mutual information. However, these measures lack the ability to d...

[Phys. Rev. E 99, 012319] Published Tue Jan 22, 2019 - Counting the number of metastable states in the modularity landscape: Algorithmic detectability limit of greedy algorithms in community detection by Tatsuro Kawamoto and Yoshiyuki Kabashima (2019/01/17 11:00)Author(s): Tatsuro Kawamoto and Yoshiyuki Kabashima
Modularity maximization using greedy algorithms continues to be a popular approach toward community detection in graphs, even after various better forming algorithms have been proposed. Apart from its clear mechanism and ease of implementation, this approach is persistently popular because, presumab...

[Phys. Rev. E 99, 010301(R)] Published Thu Jan 17, 2019 - Spinodal decomposition in a mean-field model of the cortex: Emergence of hexagonally symmetric activation patterns by Moira L. Steyn-Ross, D. A. Steyn-Ross, L. J. Voss, and J. W. Sleigh (2019/01/17 11:00)Author(s): Moira L. Steyn-Ross, D. A. Steyn-Ross, L. J. Voss, and J. W. Sleigh
Spinodal decomposition is a well-known pattern-forming mechanism in metallurgic alloys, semiconductor crystals, and colloidal gels. In metallurgy, if a heated sample of a homogeneous Zn-Al alloy is suddenly quenched below a critical temperature, then the sample can spontaneously precipitate into inh...

[Phys. Rev. E 99, 012318] Published Thu Jan 17, 2019 - Controllability and maximum matchings of complex networks by Jin-Hua Zhao and Hai-Jun Zhou (2019/01/16 11:00)Author(s): Jin-Hua Zhao and Hai-Jun Zhou
Previously, the controllability problem of a linear time-invariant dynamical system was mapped to the maximum matching (MM) problem on the bipartite representation of the underlying directed graph, and the sizes of MMs on random bipartite graphs were calculated analytically with the cavity method at...

[Phys. Rev. E 99, 012317] Published Wed Jan 16, 2019 - Localization of eigenvector centrality in networks with a cut vertex by Kieran J. Sharkey (2019/01/10 11:00)Author(s): Kieran J. Sharkey
We show that eigenvector centrality exhibits localization phenomena on networks that can be easily partitioned by the removal of a vertex cut set, the most extreme example being networks with a cut vertex. Three distinct types of localization are identified in these structures. One is related to the...

[Phys. Rev. E 99, 012315] Published Thu Jan 10, 2019 - Optimized brute-force algorithms for the bifurcation analysis of a binary neural network model by Diego Fasoli and Stefano Panzeri (2019/01/10 11:00)Author(s): Diego Fasoli and Stefano Panzeri
Bifurcation theory is a powerful tool for studying how the dynamics of a neural network model depends on its underlying neurophysiological parameters. However, bifurcation theory of neural networks has been developed mostly for mean-field limits of infinite-size spin-glass models, for finite-size dy...

[Phys. Rev. E 99, 012316] Published Thu Jan 10, 2019 - Self-avoiding walks and connective constants in clustered scale-free networks by Carlos P. Herrero (2019/01/08 11:00)Author(s): Carlos P. Herrero
Various types of walks on complex networks have been used in recent years to model search and navigation in several kinds of systems, with particular emphasis on random walks. This gives valuable information on network properties, but self-avoiding walks (SAWs) may be more suitable than unrestricted...

[Phys. Rev. E 99, 012314] Published Tue Jan 08, 2019 - Multiple phase transitions in networks of directed networks by Xueming Liu, Linqiang Pan, H. Eugene Stanley, and Jianxi Gao (2019/01/07 11:00)Author(s): Xueming Liu, Linqiang Pan, H. Eugene Stanley, and Jianxi Gao
The robustness in real-world complex systems with dependency connectivities differs from that in isolated networks. Although most complex network research has focused on interdependent undirected systems, many real-world networks—such as gene regulatory networks and traffic networks—are directed. We...

[Phys. Rev. E 99, 012312] Published Mon Jan 07, 2019 - Dynamical complexity as a proxy for the network degree distribution by A. Tlaie, I. Leyva, R. Sevilla-Escoboza, V. P. Vera-Avila, and I. Sendiña-Nadal (2019/01/07 11:00)Author(s): A. Tlaie, I. Leyva, R. Sevilla-Escoboza, V. P. Vera-Avila, and I. Sendiña-Nadal
We explore the relation between the topological relevance of a node in a complex network and the individual dynamics it exhibits. When the system is weakly coupled, the effect of the coupling strength against the dynamical complexity of the nodes is found to be a function of their topological roles,...

[Phys. Rev. E 99, 012310] Published Mon Jan 07, 2019 - Nonautonomous driving induces stability in network of identical oscillators by Maxime Lucas, Duccio Fanelli, and Aneta Stefanovska (2019/01/07 11:00)Author(s): Maxime Lucas, Duccio Fanelli, and Aneta Stefanovska
Nonautonomous driving of an oscillator has been shown to enlarge the Arnold tongue in parameter space, but little is known about the analogous effect for a network of oscillators. To test the hypothesis that deterministic nonautonomous perturbation is a good candidate for stabilizing complex dynamic...

[Phys. Rev. E 99, 012309] Published Mon Jan 07, 2019 - Structural transition in interdependent networks with regular interconnections by Xiangrong Wang, Robert E. Kooij, Yamir Moreno, and Piet Van Mieghem (2019/01/07 11:00)Author(s): Xiangrong Wang, Robert E. Kooij, Yamir Moreno, and Piet Van Mieghem
Networks are often made up of several layers that exhibit diverse degrees of interdependencies. An interdependent network consists of a set of graphs $G$ that are interconnected through a weighted interconnection matrix $B$, where the weight of each intergraph link is a non-negative real number $p$....

[Phys. Rev. E 99, 012311] Published Mon Jan 07, 2019 - Next-generation neural field model: The evolution of synchrony within patterns and waves by Áine Byrne, Daniele Avitabile, and Stephen Coombes (2019/01/07 11:00)Author(s): Áine Byrne, Daniele Avitabile, and Stephen Coombes
Neural field models are commonly used to describe wave propagation and bump attractors at a tissue level in the brain. Although motivated by biology, these models are phenomenological in nature. They are built on the assumption that the neural tissue operates in a near synchronous regime, and hence,...

[Phys. Rev. E 99, 012313] Published Mon Jan 07, 2019 - Emergence of synchronization in multiplex networks of mobile Rössler oscillators by Soumen Majhi, Dibakar Ghosh, and Jürgen Kurths (2019/01/04 11:00)Author(s): Soumen Majhi, Dibakar Ghosh, and Jürgen Kurths
Different aspects of synchronization emerging in networks of coupled oscillators have been examined prominently in the last decades. Nevertheless, little attention has been paid on the emergence of this imperative collective phenomenon in networks displaying temporal changes in the connectivity patt...

[Phys. Rev. E 99, 012308] Published Fri Jan 04, 2019 - Scaling properties of $d$-dimensional complex networks by Samuraí Brito, Thiago C. Nunes, Luciano R. da Silva, and Constantino Tsallis (2019/01/03 11:00)Author(s): Samuraí Brito, Thiago C. Nunes, Luciano R. da Silva, and Constantino Tsallis
The area of networks is very interdisciplinary and exhibits many applications in several fields of science. Nevertheless, there are few studies focusing on geographically located $d$-dimensional networks. In this paper, we study the scaling properties of a wide class of $d$-dimensional geographicall...

[Phys. Rev. E 99, 012305] Published Thu Jan 03, 2019 - Information transfer from causal history in complex system dynamics by Peishi Jiang and Praveen Kumar (2019/01/03 11:00)Author(s): Peishi Jiang and Praveen Kumar
In a multivariate evolutionary system, the present state of a variable is a resultant outcome of all interacting variables through the temporal history of the system. How can we quantify the information transfer from the history of all variables to the outcome of a specific variable at a specific ti...

[Phys. Rev. E 99, 012306] Published Thu Jan 03, 2019 - Master stability functions for complete, intralayer, and interlayer synchronization in multiplex networks of coupled Rössler oscillators by Longkun Tang, Xiaoqun Wu, Jinhu Lü, Jun-an Lu, and Raissa M. D'Souza (2019/01/03 11:00)Author(s): Longkun Tang, Xiaoqun Wu, Jinhu Lü, Jun-an Lu, and Raissa M. D'Souza
Synchronization phenomena are of broad interest across disciplines and increasingly of interest in a multiplex network setting. For the multiplex network of coupled Rössler oscillators, here we show how the master stability function, a celebrated framework for analyzing synchronization on a single n...

[Phys. Rev. E 99, 012304] Published Thu Jan 03, 2019 - Dynamic vaccination in partially overlapped multiplex network by L. G. Alvarez-Zuzek, M. A. Di Muro, S. Havlin, and L. A. Braunstein (2019/01/02 11:00)Author(s): L. G. Alvarez-Zuzek, M. A. Di Muro, S. Havlin, and L. A. Braunstein
In this work we propose and investigate a strategy of vaccination which we call “dynamic vaccination.” In our model, susceptible people become aware that one or more of their contacts are infected and thereby get vaccinated with probability $ω$, before having physical contact with any infected patie...

[Phys. Rev. E 99, 012302] Published Wed Jan 02, 2019 - Edge directionality properties in complex spherical networks by Frederik Wolf, Catrin Kirsch, and Reik V. Donner (2019/01/02 11:00)Author(s): Frederik Wolf, Catrin Kirsch, and Reik V. Donner
Spatially embedded networks have attracted increasing attention in the past decade. In this context, network characteristics have been introduced which explicitly take spatial information into account. Among others, edge directionality properties have recently gained particular interest. In this wor...

[Phys. Rev. E 99, 012301] Published Wed Jan 02, 2019 - Desynchronization and pattern formation in a noisy feed-forward oscillator network by Clément Zankoc, Duccio Fanelli, Francesco Ginelli, and Roberto Livi (2019/01/02 11:00)Author(s): Clément Zankoc, Duccio Fanelli, Francesco Ginelli, and Roberto Livi
We consider a one-dimensional directional array of diffusively coupled oscillators. They are perturbed by the injection of small additive noise, typically orders of magnitude smaller than the oscillation amplitude, and the system is studied in a region of the parameters that would yield deterministi...

[Phys. Rev. E 99, 012303] Published Wed Jan 02, 2019 - Individual-level evolutions manifest population-level scaling in complex supply networks by Likwan Cheng and Bryan W. Karney (2018/12/28 11:00)Author(s): Likwan Cheng and Bryan W. Karney
Scaling in complex supply networks is a population-level optimization phenomenon thought to arise from the evolutions of the underlying individual networks, but the evolution-scaling connection has not been empirically demonstrated. Here, using individually resolved, temporally serial, and populatio...

[Phys. Rev. E 98, 062323] Published Fri Dec 28, 2018 - Epidemic spreading with awareness diffusion on activity-driven networks by Ping Hu, Li Ding, and Xuming An (2018/12/28 11:00)Author(s): Ping Hu, Li Ding, and Xuming An
Acknowledging the significance of awareness diffusion and behavioral response in contagion outbreaks has been regarded as an indispensable prerequisite for a complete understanding of epidemic spreading. Recent studies from the research community have accumulated overwhelming evidence for the incess...

[Phys. Rev. E 98, 062322] Published Fri Dec 28, 2018 - Natural emergence of a core structure in networks via clique percolation by A. Melka, N. Slater, A. Mualem, and Y. Louzoun (2018/12/26 11:00)Author(s): A. Melka, N. Slater, A. Mualem, and Y. Louzoun
Networks are often presented as containing a “core” and a “periphery.” The existence of a core suggests that some vertices are central and form the skeleton of the network, to which all other vertices are connected. An alternative view of graphs is through communities. Multiple measures have been pr...

[Phys. Rev. E 98, 062319] Published Wed Dec 26, 2018 - Social contagions with communication channel alternation on multiplex networks by Wei Wang, Ming Tang, H. Eugene Stanley, and Lidia A. Braunstein (2018/12/26 11:00)Author(s): Wei Wang, Ming Tang, H. Eugene Stanley, and Lidia A. Braunstein
Internet communication channels, e.g., Facebook, Twitter, and email, are multiplex networks that facilitate interaction and information-sharing among individuals. During brief time periods users often use a single communication channel, but then communication channel alteration (CCA) occurs. This me...

[Phys. Rev. E 98, 062320] Published Wed Dec 26, 2018 - Estimating network structure from unreliable measurements by M. E. J. Newman (2018/12/26 11:00)Author(s): M. E. J. Newman
Most empirical studies of networks assume that the network data we are given represent a complete and accurate picture of the nodes and edges in the system of interest, but in real-world situations this is rarely the case. More often the data only specify the network structure imperfectly: Like data...

[Phys. Rev. E 98, 062321] Published Wed Dec 26, 2018 - Effects of hidden nodes on the reconstruction of bidirectional networks by Emily S. C. Ching and P. H. Tam (2018/12/21 11:00)Author(s): Emily S. C. Ching and P. H. Tam
Much research effort has been devoted to developing methods for reconstructing the links of a network from dynamics of its nodes. Many current methods require the measurements of the dynamics of all the nodes to be known. In real-world problems, it is common that either some nodes of a network of in...

[Phys. Rev. E 98, 062318] Published Fri Dec 21, 2018 - Controlling the uncertain response of real multiplex networks to random damage by Francesco Coghi, Filippo Radicchi, and Ginestra Bianconi (2018/12/19 11:00)Author(s): Francesco Coghi, Filippo Radicchi, and Ginestra Bianconi
We reveal large fluctuations in the response of real multiplex networks to random damage of nodes. These results indicate that the average response to random damage, traditionally considered in mean-field approaches to percolation, is a poor metric of system robustness. We show instead that a large-...

[Phys. Rev. E 98, 062317] Published Wed Dec 19, 2018 - Topologically robust zero-sum games and Pfaffian orientation: How network topology determines the long-time dynamics of the antisymmetric Lotka-Volterra equation by Philipp M. Geiger, Johannes Knebel, and Erwin Frey (2018/12/19 11:00)Author(s): Philipp M. Geiger, Johannes Knebel, and Erwin Frey
To explore how the topology of interaction networks determines the robustness of dynamical systems, we study the antisymmetric Lotka-Volterra equation (ALVE). The ALVE is the replicator equation of zero-sum games in evolutionary game theory, in which the strengths of pairwise interactions between st...

[Phys. Rev. E 98, 062316] Published Wed Dec 19, 2018 - Epidemic spreading and aging in temporal networks with memory by Michele Tizzani, Simone Lenti, Enrico Ubaldi, Alessandro Vezzani, Claudio Castellano, and Raffaella Burioni (2018/12/18 11:00)Author(s): Michele Tizzani, Simone Lenti, Enrico Ubaldi, Alessandro Vezzani, Claudio Castellano, and Raffaella Burioni
Time-varying network topologies can deeply influence dynamical processes mediated by them. Memory effects in the pattern of interactions among individuals are also known to affect how diffusive and spreading phenomena take place. In this paper we analyze the combined effect of these two ingredients ...

[Phys. Rev. E 98, 062315] Published Tue Dec 18, 2018 - Disassortativity of percolating clusters in random networks by Shogo Mizutaka and Takehisa Hasegawa (2018/12/18 11:00)Author(s): Shogo Mizutaka and Takehisa Hasegawa
We provide arguments for the property of the degree-degree correlations of giant components formed by the percolation process on uncorrelated random networks. Using the generating functions, we derive a general expression for the assortativity of a giant component, $r$, which is defined as Pearson's...

[Phys. Rev. E 98, 062314] Published Tue Dec 18, 2018 - Pedestrian stepping dynamics in single-file movement by Yi Ma, Ying Ying Sun, Eric Wai Ming Lee, and Richard Kowk Kit Yuen (2018/12/14 11:00)Author(s): Yi Ma, Ying Ying Sun, Eric Wai Ming Lee, and Richard Kowk Kit Yuen
Observations of large numbers of pedestrians in two new studies offer insights into how humans avoid bumping into each other.

[Phys. Rev. E 98, 062311] Published Fri Dec 14, 2018 - Physics-based modeling and data representation of pairwise interactions among pedestrians by Alessandro Corbetta, Jasper A. Meeusen, Chung-min Lee, Roberto Benzi, and Federico Toschi (2018/12/14 11:00)Author(s): Alessandro Corbetta, Jasper A. Meeusen, Chung-min Lee, Roberto Benzi, and Federico Toschi
Observations of large numbers of pedestrians in two new studies offer insights into how humans avoid bumping into each other.

[Phys. Rev. E 98, 062310] Published Fri Dec 14, 2018 - Feedback through graph motifs relates structure and function in complex networks by Yu Hu, Steven L. Brunton, Nicholas Cain, Stefan Mihalas, J. Nathan Kutz, and Eric Shea-Brown (2018/12/14 11:00)Author(s): Yu Hu, Steven L. Brunton, Nicholas Cain, Stefan Mihalas, J. Nathan Kutz, and Eric Shea-Brown
In physics, biology, and engineering, network systems abound. How does the connectivity of a network system combine with the behavior of its individual components to determine its collective function? We approach this question for networks with linear time-invariant dynamics by relating internal net...

[Phys. Rev. E 98, 062312] Published Fri Dec 14, 2018 - Mechanisms of dimensionality reduction and decorrelation in deep neural networks by Haiping Huang (2018/12/14 11:00)Author(s): Haiping Huang
Deep neural networks are widely used in various domains. However, the nature of computations at each layer of the deep networks is far from being well understood. Increasing the interpretability of deep neural networks is thus important. Here, we construct a mean-field framework to understand how co...

[Phys. Rev. E 98, 062313] Published Fri Dec 14, 2018 - Spin-glass model for the $C$-dismantling problem by Shao-Meng Qin (2018/12/12 11:00)Author(s): Shao-Meng Qin
The $C$-dismantling (CD) problem aims at finding the minimum vertex set $\mathcal{D}$ of a graph $\mathcal{G}(\mathcal{V},\mathcal{E})$ after removing which the remaining graph will break into connected components with the size not larger than $C$. In this paper, we introduce a spin-glass model with...

[Phys. Rev. E 98, 062309] Published Wed Dec 12, 2018 - Bond and site color-avoiding percolation in scale-free networks by Andrea Kadović, Sebastian M. Krause, Guido Caldarelli, and Vinko Zlatic (2018/12/10 11:00)Author(s): Andrea Kadović, Sebastian M. Krause, Guido Caldarelli, and Vinko Zlatic
Recently, the problem of classes of vulnerable vertices (represented by colors) in complex networks has been discussed, where all vertices with the same vulnerability are prone to fail together. Utilizing redundant paths each avoiding one vulnerability (color), a robust color-avoiding connectivity i...

[Phys. Rev. E 98, 062308] Published Mon Dec 10, 2018 - Computational landscape of user behavior on social media by David Darmon, William Rand, and Michelle Girvan (2018/12/10 11:00)Author(s): David Darmon, William Rand, and Michelle Girvan
With the increasing abundance of “digital footprints” left by human interactions in online environments, e.g., social media and app use, the ability to model complex human behavior has become increasingly possible. Many approaches have been proposed, however, most previous model frameworks are fairl...

[Phys. Rev. E 98, 062306] Published Mon Dec 10, 2018 - Interplay of network structure and dynamics in functional organization of the visual cortex by Yudy Carolina Daza C., Pablo M. Gleiser, and Francisco A. Tamarit (2018/12/10 11:00)Author(s): Yudy Carolina Daza C., Pablo M. Gleiser, and Francisco A. Tamarit
The functional patterns of the visual cortex observed in some mammals such as cats, primates, and humans has allowed us to understand basic principles of organization in the structure of the cortex. However, the observation of different kinds of functional arrangement in other animals such as mice, ...

[Phys. Rev. E 98, 062307] Published Mon Dec 10, 2018 - Suppression effect on the Berezinskii-Kosterlitz-Thouless transition in growing networks by S. M. Oh, S.-W. Son, and B. Kahng (2018/12/07 11:00)Author(s): S. M. Oh, S.-W. Son, and B. Kahng
The percolation transition in growing networks can be of infinite order, following the Berezinskii-Kosterlitz-Thouless (BKT) transition. Examples can be found in diverse systems, including coauthorship networks and protein interaction networks. Here, we investigate how such an infinite-order percola...

[Phys. Rev. E 98, 060301(R)] Published Fri Dec 07, 2018

##### International Journal of Quantum Information

- Comparing the randomized benchmarking figure with the average infidelity of a quantum gate-set by Jiaan Qi (2019/06/14 08:25)International Journal of Quantum Information, Ahead of Print. <br/> Randomized benchmarking (RB) is a popular procedure used to gauge the performance of a set of gates useful for quantum information processing (QIP). Recently, Proctor et al. [Phys. Rev. Lett. 119 (2017) 130502] demonstrated a practically relevant example where the RB measurements give a number [math], very different from the actual average gate-set infidelity [math], despite past theoretical assurances that the two should be equal. Here, we derive formulas for [math], and for [math] from the RB protocol, in a manner permitting easy comparison of the two. We show in general that, indeed, [math], i.e. RB does not measure average infidelity, and, in fact, neither one bounds the other. We give several examples, all plausible in real experiments, to illustrate the differences in [math] and [math]. Many recent papers on experimental implementations of QIP have claimed the ability to perform high-fidelity gates because they demonstrated small [math] values using RB. Our analysis shows that such a statement from RB alone has to be interpreted with caution.
- Suppressing the information losses of accelerated qubit–qutrit system by M. Y. Abd-Rabbou (2019/06/12 10:01)International Journal of Quantum Information, Ahead of Print. <br/> Protecting the accelerated information coherence and suppressing of its decay due to the acceleration is achieved by using different noisy channels. The behavior of three different types of information; Fisher, nonlocal and local information of qubit–qutrit system is discussed. It is shown that, the estimation rate of the acceleration parameter is maximized if both subsystems are accelerated and interacted locally with their noise channels. However, if the largest subsystem is accelerated, then the estimation rate is minimized. The rate of change of the nonlocal information depends on which subsystem is accelerated. The results display that the local information is almost unaltered during the acceleration process, that is, the information is frozen. We show that the phase-flip channel represents the weak channel, where its suppressing of the decay due to the acceleration is smaller than the dephasing and depolarize of channels.
- A novel quantum steganography scheme based on ASCII by Jia Luo (2019/06/10 11:04)International Journal of Quantum Information, Ahead of Print. <br/> Based on the novel enhanced quantum representation for quantum image (NEQR), a new blind quantum steganography scheme is proposed. In this scheme, an improved quantum representation of text utilizing American Standard Code for Information Interchange (ASCII) is provided that uses two qubit sequences to store the same quantum text message. The general embedding process of the scheme is as follows: First, the cover image of size [math] will be divided into eight blocks of size [math] and the secret quantum text of size [math] is scrambled by Gray code transform method. Then, the disorder quantum text is embedded into the eight blocks of cover image employing the Gray code as a judgment condition. Meanwhile, the corresponding quantum circuits are drawn. Through the analysis of all quantum circuits, it can be concluded that the scheme has a lower complexity that is [math]. And the performance of the proposed scheme is analyzed in terms of simulation results of three items: visual quality, capacity and robustness.
- Steering evolution of two-mode Gaussian states in noisy environments by Farkhondeh Abbasnezhad (2019/06/10 11:04)International Journal of Quantum Information, Ahead of Print. <br/> Steering, a quantum property existing in some bipartite entangled systems, causes the local measurements on one part to change the state of the other part at any distance. In this paper, the dynamics of steering between two uncoupled oscillators in squeezed thermal, thermal and vacuum environments are compared. Assuming that the two oscillators are coupled to a common environment or two similar environments, the evolution of steering is obtained using Linblad equation in Born–Markov approximation. It is observed that when the two oscillators are initially in uni-modal squeezed states, the interaction with a common squeezed thermal environment induces steering between them after a short time. However, in other common and the two similar environments, steering does not appear. In addition, when two oscillators are initially in a squeezed thermal state, it is observed that steering decreases monotonically and disappears in a short time in common thermal, common vacuum and the two similar environments. Moreover, steering survives the most in a common squeezed thermal environment.
- Geometric measures of discordlike quantum correlations based on Tsallis relative entropy by Weijing Li (2019/06/06 12:10)International Journal of Quantum Information, Ahead of Print. <br/> A kind of new geometric measure of quantum correlations is formulated. The proposed formulation is in terms of the quantum Tsallis relative entropy and can naturally be viewed as a one-parameter extension quantum discordlike measure that satisfies all requirements of a good measure of quantum correlations. It is of an elegant analytic expression and contains several existing good quantum correlation measures as special cases. The partial coherence measure is also investigated.
- Bohmian mechanics for instrumentalists by Hrvoje Nikolić (2019/05/23 05:51)International Journal of Quantum Information, Ahead of Print. <br/> We formulate Bohmian mechanics (BM) such that the main objects of concern are macroscopic phenomena, while microscopic particle trajectories only play an auxiliary role. Such a formulation makes it easy to understand why BM always makes the same measurable predictions as standard quantum mechanics (QM), irrespective of the details of microscopic trajectories. Relativistic quantum field theory (QFT) is interpreted as an effective long-distance theory that at smaller distances must be replaced by some more fundamental theory. Analogy with condensed-matter physics suggests that this more fundamental theory could have a form of nonrelativistic QM, offering a simple generic resolution of an apparent conflict between BM and relativistic QFT.
- Classical and quantum correlations for a family of two-qutrit states by Hossein Parsian (2019/05/14 08:24)International Journal of Quantum Information, Ahead of Print. <br/> The classical and quantum correlations for a family of two-qutrit states are investigated. For this purpose, a family of two-qutrit states, as well as a set of measurements are proposed. An analytical quantum discord treatment is presented for this family of two-qutrit states. Finally, we compute and illustrate the entanglement of formation, classical mutual information and quantum discord for this family of two-qutrit quantum states.
- Multi-party quantum summation with a single [math]-level quantum system by C. Zhang (2019/05/13 04:30)International Journal of Quantum Information, Ahead of Print. <br/> A multi-party quantum summation with a single [math]-level quantum system is proposed, in which a semi-honest third party (TP) is employed. Only sequential communication of a single quantum [math]-level system (for any prime [math]) is required in the presented protocol, resulting in advantages in scalability. In addition, it can be realized with state-of-the-art technology. Due to the semi-honest TP, the protocol is not only secure against outside attacks, but also secure against participant attacks.
- Cryptanalysis of He’s quantum private comparison protocol and a new protocol by WanQing Wu (2019/05/10 05:23)International Journal of Quantum Information, Ahead of Print. <br/> Recently, He proposed a novel quantum private comparison protocol without a third party (G. P. He, Int. J. Quantum Inf. 15(2) (2016) 1750014). This paper points out that two security loopholes in He’s protocol are existent. And a new QPC protocol which can avoid these loopholes is proposed without the help of a third party in this paper.
- Continuous-time quantum search and time-dependent two-level quantum systems by Carlo Cafaro (2019/05/03 08:01)International Journal of Quantum Information, Ahead of Print. <br/> It was recently emphasized by Byrnes, Forster and Tessler [Phys. Rev. Lett. 120 (2018) 060501] that the continuous-time formulation of Grover’s quantum search algorithm can be intuitively understood in terms of Rabi oscillations between the source and the target subspaces. In this work, motivated by this insightful remark and starting from the consideration of a time-independent generalized quantum search Hamiltonian as originally introduced by Bae and Kwon [Phys. Rev. A 66 (2002) 012314], we present a detailed investigation concerning the physical connection between quantum search Hamiltonians and exactly solvable time-dependent two-level quantum systems. Specifically, we compute in an exact analytical manner the transition probabilities from a source state to a target state in a number of physical scenarios specified by a spin-[math] particle immersed in an external time-dependent magnetic field. In particular, we analyze both the periodic oscillatory as well as the monotonic temporal behaviors of such transition probabilities and, moreover, explore their analogy with characteristic features of Grover-like and fixed-point quantum search algorithms, respectively. Finally, we discuss from a physics standpoint the connection between the schedule of a search algorithm, in both adiabatic and nonadiabatic quantum mechanical evolutions, and the control fields in a time-dependent driving Hamiltonian.
- Semiquantum secure direct communication with authentication based on single-photons by Ming-Ming Wang (2019/04/25 10:10)International Journal of Quantum Information, Ahead of Print. <br/> Semiquantum cryptography has drawn much attention in recent years since it simplifies the implementation of quantum cryptographic protocols. In this paper, we study semiquantum secure direct communication (SQSDC). Based on single-photons, we propose a two-step SQSDC protocol with identity authentication, which can be used to prevent impersonation and the man-in-the-middle attack. Different from previous protocols based on quantum entanglement or quantum memory, our protocol removes there restrictions for simplifying its physical implementation. We prove that our two-step SQSDC protocol is completely robust. That is, any adversarial attempting to learn some information on the secure message or identity strings will inevitably induce some errors that can be detected by communicators.
- Adiabatic demagnetization at absolute negative temperature: Generation of quantum correlations by Gregory B. Furman (2019/04/24 09:41)International Journal of Quantum Information, Ahead of Print. <br/> In this paper, we study behavior of the correlations, both quantum and classical, under adiabatic demagnetization process in systems of nuclear spins with dipole–dipole interactions in an external magnetic field and in the temperature range including positive and negative temperatures. For a two-spin system, analytical expressions for the quantum and classical correlations are obtained. It is revealed that the field dependences of the quantum and classical correlations at positive and negative temperatures are substantially different. This difference most clearly appears in the case of zero magnetic field: at negative temperature, the measures of quantum correlations tend to the maximum values with a temperature increase. At positive temperature, these quantities tend to zero at a decrease of magnetic field. It is also found that, for the nearest-neighboring spins in the same field, the values of concurrence and discord are larger at negative temperatures than at positive ones.
- Generation of elementary gates and Bell’s states using controlled adiabatic evolutions by Abderrahim Benmachiche (2019/04/09 10:25)International Journal of Quantum Information, Ahead of Print. <br/> Fundamental quantum gates can be implemented effectively using adiabatic quantum computation or circuit model. Recently, Hen combined the two approaches to introduce a new model called controlled adiabatic evolutions [I. Hen, Phys. Rev. A, 91(2) (2015) 022309]. This model was specifically designed to implement one and two-qubit controlled gates. Later, Santos extended Hen’s work to implement [math]-qubit controlled gates [A. C. Santos and M. S. Sarandy, Sci. Rep., 5 (2015) 15775]. In this paper, we discuss the implementation of each of the usual quantum gates, as well as demonstrate the possibility of preparing Bell’s states using the controlled adiabatic evolutions approach. We conclude by presenting the fidelity results of implementing single quantum gates and Bell’s states in open systems.
- Two new constructions of approximately symmetric informationally complete positive operator-valued measures by Gang Wang (2019/04/09 10:25)International Journal of Quantum Information, Ahead of Print. <br/> A symmetric informationally complete positive operator-valued measure (SIC-POVM) is a POVM in [math] consisting of [math] positive operators of rank one such that all of whose Hermite inner products are equal. SIC-POVMs are important in quantum information theory, which have many applications in quantum state tomography, quantum cryptography and basic research in quantum mechanics. However, it is very difficult to construct SIC-POVMs. Therefore, many scholars have focused on approximately symmetric informationally complete positive operator-valued measures (ASIC-POVMs) for which the Hermite inner products are close to equal. In this paper, two new constructions of ASIC-POVMs are provided by using character sums and some special functions over finite fields.
- New constructions of entanglement-assisted quantum MDS codes from negacyclic codes by Ruihu Li (2019/04/09 10:25)International Journal of Quantum Information, Ahead of Print. <br/> When constructing quantum codes under the entanglement-assisted (EA) stabilizer formalism, one can ignore the limitation of dual-containing condition. This allows us to construct EA quantum error-correcting codes (QECCs) from any classical linear codes. The main contribution of this manuscript is to make a general statement for determining the optimal number of pre-shared qubits instead of presenting only specific cases. Let [math] and [math], where [math] is an odd prime power, [math] and [math]. By deeply investigating the decomposition of the defining set of negacyclic codes, we generalize the number of pre-shared entanglement pairs of Construction (1) in Lu et al. [Quantom Inf. Process. 17 (2018) 69] from [math] to arbitrary even numbers less than or equal to [math]. Consequently, a series of EA quantum maximum distance separable (EAQMDS) codes can be produced. The absolute majority of them are new and the minimum distance can be up to [math]. Moreover, this method can be applied to construct many other families of EAQECCs with good parameters, especially large minimum distance.
- A family of system Hamiltonian in quantum adiabatic search type problem by Jie Sun (2019/04/04 08:00)International Journal of Quantum Information, Volume 17, Issue 02, March 2019. <br/> In this paper [J. Sun, S. Lu and F. Liu, Open Syst. Info. Dyn.23(3) (2016) 1650016], we have studied a general class of adiabatic evolutions in quantum adiabatic search type problem, and found another limitation on it, besides those reported in our early work. In this paper, we extend this study by considering adding an extra driving scheme to the system Hamiltonian of this type of quantum adiabatic evolution. It will be shown that, like the previous study in [J. Sun, S. Lu and F. Liu, Open Syst. Info. Dyn.23(3) (2016) 1650016], the limitation above can also possibly penetrate into the search type quantum-adiabatic computation even by this more general family of system Hamiltonian, which may shed light on what we should have in mind when solving practical problems by means of quantum adiabatic evolution.
- The quantum geometric tensor from generating functions by Javier Alvarez-Jimenez (2019/04/04 07:57)International Journal of Quantum Information, Volume 17, Issue 02, March 2019. <br/> We introduce a new method to compute the Quantum Geometric Tensor, this procedure allows us to compute the Quantum Information Metric and the Berry curvature perturbatively for a theory with an arbitrary interaction Hamiltonian. The calculation uses the generating function method, and it is illustrated with the harmonic oscillator with a linear and a quartic perturbation.
- Sub-fourier quantum metrology through bright solitary trains in Bose–Einstein condensate by Suranjana Ghosh (2019/04/04 07:55)International Journal of Quantum Information, Volume 17, Issue 02, March 2019. <br/> We propose to utilize the Bose–Einstein condensate (BEC) for precision phase sensitive measurement of position and momentum displacements. The controlled two-soliton dynamics can be turned into a quantum probe to measure these parameters with high precision in an experimentally verified system of bright solitary trains. A careful phase space analysis of the dynamics of the mesoscopic wave packet is carried out through Wigner phase space picture for finding out the parameter domain exhibiting sub-Planck structures, required for precision quantum metrology. We propose two experimentally feasible scenarios, one involving the overall phase and the other through the relative phase between the two-solitons when they are oscillating inside the trap. In both the cases, detailed analytical studies are carried out through the overlap functions which reveal the sensitivity issue. A careful analysis is also performed to find the parametric domain relevant for the use of BEC for weak value estimation.
- A geometrization of quantum mutual information by Davide Pastorello (2019/04/04 07:55)International Journal of Quantum Information, Volume 17, Issue 02, March 2019. <br/> It is well known that quantum mechanics admits a geometric formulation on the complex projective space as a Kähler manifold. In this paper, we consider the notion of mutual information among continuous random variables in relation to the geometric description of a composite quantum system introducing a new measure of total correlations that can be computed in terms of Gaussian integrals.
- Double CNOT attack on “Quantum key distribution with limited classical Bob” by Po-Hua Lin (2019/04/04 07:53)International Journal of Quantum Information, Volume 17, Issue 02, March 2019. <br/> This paper points out a security loophole in the Quantum key distribution with limited classical Bob [Int. J. Quantum Inf. 11(01) (2013) 1350005]. With the loophole, an eavesdropper can perform the double CNOT attack to reveal about [math]-bits out of an [math]-bit key without being detected by the protocol.
- Decoy state quantum-key-distribution by using odd coherent states without monitoring signal disturbance by Shujing Li (2019/04/04 07:51)International Journal of Quantum Information, Volume 17, Issue 02, March 2019. <br/> Recently, a novel quantum-key-distribution (QKD) protocol, called Round-robin-differential-phase-shift (RRDPS) QKD, has been proposed to share a secure key without monitoring the signal disturbance. In this paper, we propose a decoy state RRDPS-QKD protocol with odd coherent states (OCS). We implement a one-intensity decoy state method into the RRDPS-QKD with OCS to estimate the key rate. The results show that both the maximum transmission distance and the key rate of our protocol are significantly improved. Moreover, only one-intensity decoy state is sufficient for the protocol to approach the asymptotic limit with infinite decoy states.
- A study and analysis of a discrete quantum walk-based hybrid clustering approach using [math]-regular bipartite graph and 1D lattice by Sanjay Chakraborty (2019/04/04 07:49)International Journal of Quantum Information, Volume 17, Issue 02, March 2019. <br/> Traditional machine learning shares several benefits with quantum information processing field. The study of machine learning with quantum mechanics is called quantum machine learning. Data clustering is an important tool for machine learning where quantum computing plays a vital role in its inherent speed up capability. In this paper, a hybrid quantum algorithm for data clustering (quantum walk-based hybrid clustering (QWBHC)) is introduced where one-dimensional discrete time quantum walks (DTQW) play the central role to update the positions of data points according to their probability distributions. A quantum oracle is also designed and it is mainly implemented on a finite [math]-regular bipartite graph where data points are initially distributed as a predefined set of clusters. An overview of a quantum walk (QW) based clustering algorithm on 1D lattice structure is also introduced and described in this paper. In order to search the nearest neighbors, a unitary and reversible DTQW gives a quadratic speed up over the traditional classical random walk. This paper also demonstrates the comparisons of our proposed hybrid quantum clustering algorithm with some state-of-the-art clustering algorithms in terms of clustering accuracy and time complexity analysis. The proposed quantum oracle needs [math] queries to mark the nearest data points among clusters and modify the existing clusters. Finally, the proposed QWBHC algorithm achieves [math] performance.
- Condition for zero and nonzero discord in graph Laplacian quantum states by Supriyo Dutta (2019/04/04 07:49)International Journal of Quantum Information, Volume 17, Issue 02, March 2019. <br/> This work is at the interface of graph theory and quantum mechanics. Quantum correlations epitomize the usefulness of quantum mechanics. Quantum discord is an interesting facet of bipartite quantum correlations. Earlier, it was shown that every combinatorial graph corresponds to quantum states whose characteristics are reflected in the structure of the underlined graph. A number of combinatorial relations between quantum discord and simple graphs were studied. To extend the scope of these studies, we need to generalize the earlier concepts applicable to simple graphs to weighted graphs, corresponding to a diverse class of quantum states. To this effect, we determine the class of quantum states whose density matrix representation can be derived from graph Laplacian matrices associated with a weighted directed graph and call them graph Laplacian quantum states. We find the graph theoretic conditions for zero and nonzero quantum discord for these states. We apply these results on some important pure two qubit states, as well as a number of mixed quantum states, such as the Werner, Isotropic, and [math]-states. We also consider graph Laplacian states corresponding to simple graphs as a special case.
- Synchronized preparation of bi- and tri-qubit entanglement with nitrogen-vacancy centers coupled to microtoroidal resonators by Tai-An Wang (2019/04/04 07:49)International Journal of Quantum Information, Volume 17, Issue 02, March 2019. <br/> We research the input–output process with nitrogen-vacancy (NV) centers fixed on the surface of micro-toroidal resonators (MTRs) with whispering-gallery modes (WGMs) and then present an efficient scheme for the synchronized generation of Bell and W states. In our scheme, entanglement can be prepared with the assistance of the polarized photon pulse and electron spin state of NV center. The analysis of the efficiency shows that our scheme is feasible with the current technology, which can be further used for quantum information processing.
- Research on error-correction algorithm of high-speed QKD system based on FPGA by Shi-Biao Tang (2019/04/04 07:49)International Journal of Quantum Information, Volume 17, Issue 02, March 2019. <br/> In the process of quantum key distribution (QKD), error correction algorithm is used to correct the error bits of the key at both ends. The existing applied QKD system has a low key rate and is generally Kbps of magnitude. Therefore, the performance requirement of data processing such as error correction is not high. In order to cope with the development demand of high-speed QKD system in the future, this paper introduces the Winnow algorithm to realize high-speed parity and hamming error correction based on Field Programmable Gate Array (FPGA), and explores the performance limit of this algorithm. FPGA hardware implementation can achieve the scale of Mbps bandwidth, with choosing different group length of sifted key by different error rate, and can achieve higher error correction efficiency by reducing the information leakage in the process of error correction, and improves the QKD system’s secure key rate, thus helping the future high-speed QKD system.

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