PRA: Quantum information

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Recently published articles in Phys. Rev. A in the Table of Content section "Quantum information"
Updated: 40 min 40 sec ago

Witnessing entanglement in trapped-ion quantum error correction under realistic noise

Fri, 2024-05-10 12:00

Author(s): Andrea Rodriguez-Blanco, Farid Shahandeh, and Alejandro Bermudez

Quantum error correction (QEC) exploits redundancy by encoding logical information into multiple physical qubits. In current implementations of QEC, sequences of nonperfect two-qubit entangling gates are used to codify the information redundantly into multipartite entangled states. Also, to extract …


[Phys. Rev. A 109, 052417] Published Fri May 10, 2024

Categories: Journals, Physics

Nonlocal quantum state ensembles and quantum data hiding

Fri, 2024-05-10 12:00

Author(s): Donghoon Ha and Jeong San Kim

We consider the discrimination of bipartite quantum states and establish a relation between a nonlocal quantum state ensemble and quantum data-hiding processing. Using a bound on the optimal local discrimination of bipartite quantum states, we provide a sufficient condition for a bipartite quantum s…


[Phys. Rev. A 109, 052418] Published Fri May 10, 2024

Categories: Journals, Physics

Frobenius light cone and the shift unitary

Fri, 2024-05-10 12:00

Author(s): Chao Yin, Andrew Lucas, and David T. Stephen

We bound the time necessary to implement the shift unitary on a one-dimensional ring, both by using local Hamiltonians and those with power-law interactions. This time is constrained by the Frobenius light cone; hence we prove that (for certain power-law exponents) shift unitaries cannot be implemen…


[Phys. Rev. A 109, 052419] Published Fri May 10, 2024

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Probabilistic imaginary-time evolution algorithm based on nonunitary quantum circuits

Thu, 2024-05-09 12:00

Author(s): Hao-Nan Xie, Shi-Jie Wei, Fan Yang, Zheng-An Wang, Chi-Tong Chen, Heng Fan, and Gui-Lu Long

Imaginary-time evolution is a powerful tool in the study of quantum physics. However, existing classical algorithms for simulating imaginary-time evolution suffer from high computational complexity as the dimension of the quantum system increases. In this study we propose a quantum algorithm for imp…


[Phys. Rev. A 109, 052414] Published Thu May 09, 2024

Categories: Journals, Physics

Single-shot labeling of quantum observables

Thu, 2024-05-09 12:00

Author(s): Nidhin Sudarsanan Ragini and Mario Ziman

We identify and study a particular class of distinguishability problems for quantum observables (positive-operator-valued measures), in which observables with permuted effects are involved, which we call the labeling problem. Consequently, we identify binary observables, which can be labeled perfect…


[Phys. Rev. A 109, 052415] Published Thu May 09, 2024

Categories: Journals, Physics

Continuous-variable quantum computation of the O(3) model in $1+1$ dimensions

Wed, 2024-05-08 12:00

Author(s): Raghav G. Jha, Felix Ringer, George Siopsis, and Shane Thompson

We formulate the O(3) nonlinear sigma model in 1+1 dimensions as a limit of a three-component scalar field theory restricted to the unit sphere in the large squeezing limit. This allows us to describe the model in terms of the continuous-variable (CV) approach to quantum computing. We construct the …


[Phys. Rev. A 109, 052412] Published Wed May 08, 2024

Categories: Journals, Physics

Epsilon measures of state-based quantum resource theory

Wed, 2024-05-08 12:00

Author(s): Yu Luo, Fanxu Meng, and Youle Wang

The quantification of state-based quantum “resources” such as entanglement, coherence, and nonstabilizer states lies at the heart of quantum science and technology, providing potential advantages over classical methods. In a realistic scenario, due to the imperfections and uncertainties in physical …


[Phys. Rev. A 109, 052413] Published Wed May 08, 2024

Categories: Journals, Physics

Dissipatively stabilized superposition of squeezed coherent states via periodically breaking the qubit inversion symmetry

Tue, 2024-05-07 12:00

Author(s): Peng Xie, Xing-chen Wang, Jing-wei Wang, Xin-ke Li, Yuan Zhou, Guang-hui Wang, Fazal Badshah, and Yong-chen Xiong

We propose a scheme to dissipatively stabilize superpositions of squeezed coherent states for single- and two-resonator modes in superconducting circuits, where a superconducting qubit is coupled to a single or two parametrically driven transmission-line resonators with different circuit designs. A …


[Phys. Rev. A 109, 052409] Published Tue May 07, 2024

Categories: Journals, Physics

Quantum-assisted Hilbert-space Gaussian process regression

Tue, 2024-05-07 12:00

Author(s): Ahmad Farooq, Cristian A. Galvis-Florez, and Simo Särkkä

Gaussian processes are probabilistic models that are commonly used as functional priors in machine learning. Due to their probabilistic nature, they can be used to capture prior information on the statistics of noise, smoothness of the functions, and training data uncertainty. However, their computa…


[Phys. Rev. A 109, 052410] Published Tue May 07, 2024

Categories: Journals, Physics

Predicting the onset of quantum synchronization using machine learning

Tue, 2024-05-07 12:00

Author(s): F. Mahlow, B. Çakmak, G. Karpat, İ. Yalçınkaya, and F. F. Fanchini

In an open system, environment-induced synchronization can occur between the expectation values of spin observables of a pair of qubits. Here, the authors apply a machine learning method to predict the emergence of such synchronization.


[Phys. Rev. A 109, 052411] Published Tue May 07, 2024

Categories: Journals, Physics

Inner bounding the quantum entropy cone with subadditivity and subsystem coarse grainings

Mon, 2024-05-06 12:00

Author(s): Temple He, Veronika E. Hubeny, and Massimiliano Rota

We show via explicit construction that all the extreme rays of both the three-party quantum entropy cone and the four-party stabilizer entropy cone can be obtained from subsystem coarse grainings of specific higher-party quantum states, namely, extreme states characterized by saturating a (nontrivia…


[Phys. Rev. A 109, 052407] Published Mon May 06, 2024

Categories: Journals, Physics

Unbreakable and breakable quantum censorship

Mon, 2024-05-06 12:00

Author(s): Julien Pinske and Jan Sperling

A protocol for regulating the distribution of quantum information between multiple parties is put forward. To prohibit the unrestricted distribution of quantum-resource states in a public quantum network, agents can apply a resource-destroying map to each sender's channel. Since resource-destroying …


[Phys. Rev. A 109, 052408] Published Mon May 06, 2024

Categories: Journals, Physics

No-go theorem for entanglement distillation using catalysis

Fri, 2024-05-03 12:00

Author(s): Ludovico Lami, Bartosz Regula, and Alexander Streltsov

Not all entanglement is distillable, i.e., extractable in pure form. In this work, the authors show that being assisted by catalysts, which generally can help transform quantum states, is not enough to change this; certain entangled states will stay “bound entangled” even when catalysts are allowed.


[Phys. Rev. A 109, L050401] Published Fri May 03, 2024

Categories: Journals, Physics

Iterative layerwise training for the quantum approximate optimization algorithm

Thu, 2024-05-02 12:00

Author(s): Xinwei Lee, Xinjian Yan, Ningyi Xie, Dongsheng Cai, Yoshiyuki Saito, and Nobuyoshi Asai

The capability of the quantum approximate optimization algorithm (QAOA) in solving combinatorial optimization problems has been intensively studied in recent years due to its application in the quantum-classical hybrid regime. Despite having difficulties that are innate in the variational quantum al…


[Phys. Rev. A 109, 052406] Published Thu May 02, 2024

Categories: Journals, Physics

Impact of an imperfect sampling device on the security of a continuous-variable source-independent quantum random-number generator with a phase-randomized local oscillator

Wed, 2024-05-01 12:00

Author(s): Yuanhao Li, Yangyang Fei, Weilong Wang, Xiangdong Meng, Hong Wang, Qianheng Duan, Yu Han, and Zhi Ma

Continuous-variable source-independent quantum random-number generators (CV-SI-QRNGs) generate high-speed secure random numbers without any assumptions about source. Recently, Smith et al. [Phys. Rev. A 99, 062326 (2019)] proposed a CV-SI-QRNG with phase-randomized local oscillator (LO) protocol, wh…


[Phys. Rev. A 109, 052401] Published Wed May 01, 2024

Categories: Journals, Physics

Optimization for the propagation of a multiparticle quantum walk in a one-dimensional lattice

Wed, 2024-05-01 12:00

Author(s): Daer Feng and Shengshi Pang

The quantum walk is a quantum counterpart of the classical random walk that exhibits nonclassical behaviors and outperforms the classical random walk in various aspects. It has been known that a single particle can be propagated by a discrete-time quantum walk with a quadratic time scaling in the va…


[Phys. Rev. A 109, 052402] Published Wed May 01, 2024

Categories: Journals, Physics

Hybrid quantum-gap-estimation algorithm using a filtered time series

Wed, 2024-05-01 12:00

Author(s): Woo-Ram Lee, Ryan Scott, and V. W. Scarola

Quantum simulation advantage over classical memory limitations would allow compact quantum circuits to yield insight into intractable quantum many-body problems, but the interrelated obstacles of large circuit depth in quantum time evolution and noise seem to rule out unbiased quantum simulation in …


[Phys. Rev. A 109, 052403] Published Wed May 01, 2024

Categories: Journals, Physics

Dynamics of qudit gates and effects of spectator modes on optimal control pulses

Wed, 2024-05-01 12:00

Author(s): A. Barış Özgüler and Joshua A. Job

Qudit gates for high-dimensional quantum computing can be synthesized with high precision using numerical quantum optimal control techniques. Large circuits are broken down into modules and the tailored pulses for each module can be used as primitives for a qudit compiler. Application of the pulses …


[Phys. Rev. A 109, 052404] Published Wed May 01, 2024

Categories: Journals, Physics

Boosting coherence-based protocols with correlated catalysts

Wed, 2024-05-01 12:00

Author(s): Priyabrata Char, Ajoy Sen, Amit Bhar, Indrani Chattopadhyay, and Debasis Sarkar

We explore the potential impact of the recently introduced correlated approximate catalytic procedure on quantum information processing tasks, particularly focusing on phase and subchannel discrimination protocols. Our findings reveal that the correlated catalyst substantially enhances the efficienc…


[Phys. Rev. A 109, 052405] Published Wed May 01, 2024

Categories: Journals, Physics

Asymmetric entanglement for quantum target sensing

Tue, 2024-04-30 12:00

Author(s): Su-Yong Lee, Jihwan Kim, Zaeill Kim, and Duk Y. Kim

Entanglement is beneficial to enhancing a phase sensitivity beyond the classical limit that is given by a coherent state. The best performance is achieved with symmetric entangled states, which is enhanced further by sending more photons to the signal mode. We delve into which entanglement structure…


[Phys. Rev. A 109, 042429] Published Tue Apr 30, 2024

Categories: Journals, Physics