PRA: Quantum information

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Recently published articles in Phys. Rev. A in the Table of Content section "Quantum information"
Updated: 24 min 10 sec ago

Adaptive Bayesian quantum algorithm for phase estimation

Thu, 2024-04-11 12:00

Author(s): Joseph G. Smith, Crispin H. W. Barnes, and David R. M. Arvidsson-Shukur

Quantum-phase-estimation algorithms are critical subroutines in many applications for quantum computers and in quantum-metrology protocols. These algorithms estimate the unknown strength of a unitary evolution. By using coherence or entanglement to sample the unitary Ntot times, the variance of the …


[Phys. Rev. A 109, 042412] Published Thu Apr 11, 2024

Categories: Journals, Physics

Terahertz-mediated microwave-to-optical transduction

Wed, 2024-04-10 12:00

Author(s): Furkan Sahbaz, James N. Eckstein, Dale J. Van Harlingen, and Simeon I. Bogdanov

Transduction of quantum signals between the microwave and the optical ranges will unlock powerful hybrid quantum systems enabling information processing with superconducting qubits and low-noise quantum networking through optical photons. Most microwave-to-optical quantum transducers suffer from the…


[Phys. Rev. A 109, 042409] Published Wed Apr 10, 2024

Categories: Journals, Physics

Robustness of chaotic behavior in iterated quantum protocols

Wed, 2024-04-10 12:00

Author(s): Attila Portik, Orsolya Kálmán, Igor Jex, and Tamás Kiss

One of the simplest possible quantum circuits, consisting of a cnot gate, a Hadamard gate, and a measurement on one of the outputs is known to lead to chaotic dynamics when applied iteratively on an ensemble of equally prepared qubits. The evolution of pure initial quantum states is characterized by…


[Phys. Rev. A 109, 042410] Published Wed Apr 10, 2024

Categories: Journals, Physics

Achieving metrological limits using ancilla-free quantum error-correcting codes

Tue, 2024-04-09 12:00

Author(s): Sisi Zhou, Argyris Giannisis Manes, and Liang Jiang

Quantum error correction (QEC) is theoretically capable of achieving the ultimate estimation limits in noisy quantum metrology. However, existing quantum error-correcting codes designed for noisy quantum metrology generally exploit entanglement between one probe and one noiseless ancilla of the same…


[Phys. Rev. A 109, 042406] Published Tue Apr 09, 2024

Categories: Journals, Physics

Quantum change point and entanglement distillation

Tue, 2024-04-09 12:00

Author(s): Abhishek Banerjee, Pratapaditya Bej, and Somshubhro Bandyopadhyay

In a quantum change point problem, a source emitting particles in a fixed quantum state (default) switches to a different state at some stage, and the objective is to identify when the change happened by measuring a sequence of particles emitted from such a source. Motivated by entanglement-sharing …


[Phys. Rev. A 109, 042407] Published Tue Apr 09, 2024

Categories: Journals, Physics

Incorporating encoding into quantum system design

Tue, 2024-04-09 12:00

Author(s): Alastair Kay

When creating a quantum system whose natural dynamics provide useful computational operations, designers have two key tools at their disposal: the (constrained) choice of both the Hamiltonian and the the initial state of the system (an encoding). Typically, we fix the design and utilize encodings po…


[Phys. Rev. A 109, 042408] Published Tue Apr 09, 2024

Categories: Journals, Physics

Robustness- and weight-based resource measures without convexity restriction: Multicopy witness and operational advantage in static and dynamical quantum resource theories

Mon, 2024-04-08 12:00

Author(s): Kohdai Kuroiwa, Ryuji Takagi, Gerardo Adesso, and Hayata Yamasaki

Quantum resource theories (QRTs) provide a unified framework to analyze quantum properties as resources for achieving advantages in quantum information processing. The generalized robustness and the weight of resource have been gaining increasing attention as useful resource quantifiers. However, th…


[Phys. Rev. A 109, 042403] Published Mon Apr 08, 2024

Categories: Journals, Physics

Bounds on Rényi entropy growth in many-body quantum systems

Mon, 2024-04-08 12:00

Author(s): Zhengyan Darius Shi

We prove rigorous bounds on the growth of α-Rényi entropies Sα(t) (the von Neumann entropy being the special case α=1) associated with any subsystem A of a general lattice quantum many-body system with finite on-site Hilbert space dimension. For completely nonlocal Hamiltonians, we show that the ins…


[Phys. Rev. A 109, 042404] Published Mon Apr 08, 2024

Categories: Journals, Physics

Shortest evolution path between two mixed states and its realization

Mon, 2024-04-08 12:00

Author(s): Jie-Hui Huang, Shan-Shan Dong, Guang-Long Chen, Nan-Run Zhou, Fu-Yao Liu, and Li-Guo Qin

In a quantum unitary system, an initial state may have different paths to evolve to a target state, and the only requirement is that the initial and target states share the same eigenvalue spectrum. We focus on the evolution between two nondegenerate mixed states in this paper, and investigate the s…


[Phys. Rev. A 109, 042405] Published Mon Apr 08, 2024

Categories: Journals, Physics

Efficient quantum state preparation with Walsh series

Mon, 2024-04-01 12:00

Author(s): Julien Zylberman and Fabrice Debbasch

An approximate quantum state preparation method is introduced, called the Walsh series loader (WSL). The WSL approximates quantum states defined by real-value functions of single real variables with a depth independent of the number n of qubits. Two approaches are presented. The first one approximat…


[Phys. Rev. A 109, 042401] Published Mon Apr 01, 2024

Categories: Journals, Physics

Certification of genuine multipartite entanglement in spin ensembles with measurements of total angular momentum

Mon, 2024-04-01 12:00

Author(s): Khoi-Nguyen Huynh-Vu, Lin Htoo Zaw, and Valerio Scarani

We introduce entanglement witnesses for spin ensembles which detect genuine multipartite entanglement using only measurements of the total angular momentum. States that are missed by most other angular-momentum-based witnesses for spin ensembles, which include Greenberger-Horne-Zeilinger states and …


[Phys. Rev. A 109, 042402] Published Mon Apr 01, 2024

Categories: Journals, Physics

Entanglement of magnetically levitated massive Schrödinger cat states by induced dipole interaction

Thu, 2024-03-28 12:00

Author(s): Ryan J. Marshman, Sougato Bose, Andrew Geraci, and Anupam Mazumdar

The authors present a scheme for probing the magnetically induced dipolar interactions between neighboring interferometers. They study how the scheme could also be used to study the Casimir effect in this new regime, thus understanding the background interactions in future experiments exploring the quantum nature of gravity.


[Phys. Rev. A 109, L030401] Published Thu Mar 28, 2024

Categories: Journals, Physics

Protocols for counterfactual and twin-field quantum digital signatures

Wed, 2024-03-27 12:00

Author(s): Vinod N. Rao, Shrikant Utagi, Anirban Pathak, and R. Srikanth

Quantum digital signature (QDS) is the quantum version of its classical counterpart and can offer security against attacks of repudiation, signature forging, and external eavesdropping on the basis of quantum-mechanical no-go principles. Here we propose a QDS scheme based on quantum counterfactualit…


[Phys. Rev. A 109, 032435] Published Wed Mar 27, 2024

Categories: Journals, Physics

Explicit error-correction scheme and code distance for bosonic codes with rotational symmetry

Wed, 2024-03-27 12:00

Author(s): Benjamin Marinoff, Miles Bush, and Joshua Combes

Bosonic codes with rotational symmetry are currently one of the best-performing quantum error-correcting codes. Little is known about error propagation and code distance for these rotation codes in contrast with qubit codes and bosonic codes with translation symmetry. We use a general purpose error …


[Phys. Rev. A 109, 032436] Published Wed Mar 27, 2024

Categories: Journals, Physics

Quantum parton shower with kinematics

Tue, 2024-03-26 12:00

Author(s): Christian W. Bauer, So Chigusa, and Masahito Yamazaki

Parton showers, which can efficiently incorporate quantum interference effects, have been shown to be run efficiently on quantum computers. However, so far these quantum parton showers have not included the full kinematical information required to reconstruct an event, which in classical parton show…


[Phys. Rev. A 109, 032432] Published Tue Mar 26, 2024

Categories: Journals, Physics

Tailoring quantum error correction to spin qubits

Tue, 2024-03-26 12:00

Author(s): Bence Hetényi and James R. Wootton

Spin qubits in semiconductor structures bring the promise of large-scale two-dimensional integration, with the possibility to incorporate the control electronics on the same chip. In order to perform error correction on this platform, the characteristic features of spin qubits need to be accounted f…


[Phys. Rev. A 109, 032433] Published Tue Mar 26, 2024

Categories: Journals, Physics

Adaptive quantum state estimation for two optical point sources

Tue, 2024-03-26 12:00

Author(s): Masataka Kimizu, Fuyuhiko Tanaka, and Akio Fujiwara

The authors propose a way to estimate object features smaller than the Rayleigh resolution limit, specifically the centroid location and the separation between two point sources. They explicitly provide an optimal measurement and show how it can be implemented numerically using adaptive quantum state estimation.


[Phys. Rev. A 109, 032434] Published Tue Mar 26, 2024

Categories: Journals, Physics

Metrology of weak quantum perturbations

Mon, 2024-03-25 12:00

Author(s): Sidali Mohammdi, Matteo Bina, Abdelhakim Gharbi, and Matteo G. A. Paris

We consider quantum systems with a Hamiltonian containing a weak perturbation, i.e., H=H0+λ·H̃, λ={λ1,λ2,...,}, H̃ ={H1,H2,...,}, |λ|≪1, and address situations where H̃ is known but the values of the couplings λ are unknown and should be determined by performing measurements on the system. We consid…


[Phys. Rev. A 109, 032427] Published Mon Mar 25, 2024

Categories: Journals, Physics

Non-Hermitian topological excitation transmission in the dimerized lattice with imaginary potential and nonreciprocal hopping

Mon, 2024-03-25 12:00

Author(s): Lu Qi, Qiao-Nan Li, Ning Han, Mingzhu Li, Xiu-Yun Zhang, and Ai-Lei He

We investigate the topological edge transmission of excitation based on the one-dimensional Su-Schrieffer-Heeger lattice with purely imaginary on-site potential and nonreciprocal nearest-neighbor hopping. We find that, when the system has only the nonreciprocal intracell hopping, the topological exc…


[Phys. Rev. A 109, 032428] Published Mon Mar 25, 2024

Categories: Journals, Physics

Polynomial optimization with linear combination of unitaries

Mon, 2024-03-25 12:00

Author(s): Lei Cheng, Pan Gao, Tiejun Wang, and Keren Li

In optimization, a pivotal challenge involves minimizing or maximizing polynomial functions, which is often tackled through iterative methods. Although quantum algorithms hold promise to enhance these techniques, a practical quantum protocol is still elusive. In this paper, first, we utilize the lin…


[Phys. Rev. A 109, 032429] Published Mon Mar 25, 2024

Categories: Journals, Physics