Journals

Reply to “Comment on ‘Saturating quantum advantages in postselected metrology with the positive Kirkwood-Dirac distribution' ”

PRA: Quantum information - Fri, 2024-06-21 12:00

Author(s): Sourav Das, Subhrajit Modak, and Manabendra Nath Bera

In Das et al. [Phys. Rev. A 107, 042413 (2023)], we showed that Kirkwood-Dirac negativity is not necessary to achieve anomalous quantum Fisher information. Arvidsson-Shukur et al. [preceding Comment, Phys. Rev. A (to be published)] claim that one of our conclusions is wrong. Here, we argue that the …


[Phys. Rev. A 109, 066402] Published Fri Jun 21, 2024

Categories: Journals, Physics

Parameter shift rule with optimal phase selection

PRA: Quantum information - Fri, 2024-06-21 12:00

Author(s): Liubov Markovich, Savvas Malikis, Stefano Polla, and Jordi Tura

Parameter shift rules enable the estimation of the derivatives of expectation values with respect to the dynamical evolution of a state. Thus, they provide a valuable tool in variational optimization and insight into the dynamical behavior of quantum systems. Constructing parameter shift rules appli…


[Phys. Rev. A 109, 062429] Published Fri Jun 21, 2024

Categories: Journals, Physics

Robust Quantum Gates against Correlated Noise in Integrated Quantum Chips

Author(s): Kangyuan Yi, Yong-Ju Hai, Kai Luo, Ji Chu, Libo Zhang, Yuxuan Zhou, Yao Song, Song Liu, Tongxing Yan, Xiu-Hao Deng, Yuanzhen Chen, and Dapeng Yu

As quantum circuits become more integrated and complex, additional error sources that were previously insignificant start to emerge. Consequently, the fidelity of quantum gates benchmarked under pristine conditions falls short of predicting their performance in realistic circuits. To overcome this p…


[Phys. Rev. Lett. 132, 250604] Published Thu Jun 20, 2024

Categories: Journals, Physics

Wide-Band Unambiguous Quantum Sensing via Geodesic Evolution

Author(s): Ke Zeng, Xiaohui Yu, Martin B. Plenio, and Zhen-Yu Wang

We present a quantum sensing technique that utilizes a sequence of π pulses to cyclically drive the qubit dynamics along a geodesic path of adiabatic evolution. This approach effectively suppresses the effects of both decoherence noise and control errors while simultaneously removing unwanted resona…


[Phys. Rev. Lett. 132, 250801] Published Thu Jun 20, 2024

Categories: Journals, Physics

Multiparticle entanglement classification with the ergotropic gap

PRA: Quantum information - Thu, 2024-06-20 12:00

Author(s): Xue Yang, Yan-Han Yang, Shao-Ming Fei, and Ming-Xing Luo

The presence of quantum multipartite entanglement implies the existence of a thermodynamic quantity known as the ergotropic gap, which is defined as the difference between the maximal global and local extractable works from the system. We establish a direct relation between the geometric measure of …


[Phys. Rev. A 109, 062427] Published Thu Jun 20, 2024

Categories: Journals, Physics

Enhancement of nonstabilizerness within indefinite causal order

PRA: Quantum information - Thu, 2024-06-20 12:00

Author(s): Yin Mo, Chengkai Zhu, Zhiping Liu, Mingrui Jing, and Xin Wang

In quantum computing, the nonstabilizerness of quantum operations is crucial for understanding and quantifying quantum speedups. In this study, we explore the phenomena of nonstabilizerness of the quantum SWITCH, a novel structure that allows quantum states to pass through operations in a superposit…


[Phys. Rev. A 109, 062428] Published Thu Jun 20, 2024

Categories: Journals, Physics

Single-Electron Qubits Based on Quantum Ring States on Solid Neon Surface

Author(s): Toshiaki Kanai, Dafei Jin, and Wei Guo

Single electrons trapped on solid-neon surfaces have recently emerged as a promising platform for charge qubits. Experimental results have revealed their exceptionally long coherence times, yet the actual quantum states of these trapped electrons, presumably on imperfectly flat neon surfaces, remain…


[Phys. Rev. Lett. 132, 250603] Published Tue Jun 18, 2024

Categories: Journals, Physics

Generalized physically incoherent operations

PRA: Quantum information - Tue, 2024-06-18 12:00

Author(s): Ping Li and Yongming Li

Quantum coherence is an intrinsic property within a single quantum system. Many different coherent resource theories have been proposed to characterize this property within the framework of resource theory. This difference is based on the difference in the identification of “free” operations. In thi…


[Phys. Rev. A 109, 062424] Published Tue Jun 18, 2024

Categories: Journals, Physics

Quantum sequential scattering model for quantum state learning

PRA: Quantum information - Tue, 2024-06-18 12:00

Author(s): Mingrui Jing, Geng Liu, Hongbin Ren, and Xin Wang

Learning probability distribution is an essential framework in classical learning theory. As a counterpart, quantum state learning has spurred the exploration of quantum machine learning theory. However, as dimensionality increases, learning a high-dimensional unknown quantum state via conventional …


[Phys. Rev. A 109, 062425] Published Tue Jun 18, 2024

Categories: Journals, Physics

Near-threshold qudit stabilizer codes with efficient encoding circuits for magic-state distillation

PRA: Quantum information - Tue, 2024-06-18 12:00

Author(s): Abhi Kumar Sharma and Shayan Srinivasa Garani

Magic-state distillation is a protocol to purify noisy quantum states using quantum stabilizer codes. In this paper, we provide conditions for identifying magic states along with analytical expressions for computing the noise threshold. Through quantum entropic results, we prove the convergence of t…


[Phys. Rev. A 109, 062426] Published Tue Jun 18, 2024

Categories: Journals, Physics

X-Ray Emission from Atomic Systems Can Distinguish between Prevailing Dynamical Wave-Function Collapse Models

Author(s): Kristian Piscicchia, Sandro Donadi, Simone Manti, Angelo Bassi, Maaneli Derakhshani, Lajos Diósi, and Catalina Curceanu

In this work the spontaneous electromagnetic radiation from atomic systems, induced by dynamical wave-function collapse, is investigated in the x-ray domain. Strong departures are evidenced with respect to the simple cases considered until now in the literature, in which the emission is either perfe…


[Phys. Rev. Lett. 132, 250203] Published Tue Jun 18, 2024

Categories: Journals, Physics

Ultrahigh-Precision Hamiltonian Parameter Estimation in a Superconducting Circuit

Author(s): Sai Li, De-Jian Pan, Yuan-Ke Zhu, Jia-Lang Zhou, Wen-Cui Liao, Wei-Xin Zhang, Zhen-Tao Liang, Qing-Xian Lv, Haifeng Yu, Zheng-Yuan Xue, Hui Yan, and Shi-Liang Zhu

The Hamiltonian, which determines the evolution of a quantum system, is fundamental in quantum physics. Therefore, it is crucial to implement high-precision generation and measurement of the Hamiltonian in a practical quantum system. Here, we experimentally demonstrate ultrahigh-precision Hamiltonia…


[Phys. Rev. Lett. 132, 250204] Published Tue Jun 18, 2024

Categories: Journals, Physics

Understanding Central Spin Decoherence Due to Interacting Dissipative Spin Baths

Author(s): Mykyta Onizhuk, Yu-Xin Wang (王语馨), Jonah Nagura, Aashish A. Clerk, and Giulia Galli

We propose a new approach to simulate the decoherence of a central spin coupled to an interacting dissipative spin bath with cluster-correlation expansion techniques. We benchmark the approach on generic 1D and 2D spin baths and find excellent agreement with numerically exact simulations. Our calcul…


[Phys. Rev. Lett. 132, 250401] Published Tue Jun 18, 2024

Categories: Journals, Physics

Exact Steering Bound for Two-Qubit Werner States

Author(s): Yujie Zhang and Eric Chitambar

Two independent papers answer an important open question by showing that generalized measurements are not more powerful than projection-valued measurements in quantum steering with two-qubit Werner states.


[Phys. Rev. Lett. 132, 250201] Published Mon Jun 17, 2024

Categories: Journals, Physics

Compatibility of Generalized Noisy Qubit Measurements

Author(s): Martin J. Renner

Two independent papers answer an important open question by showing that generalized measurements are not more powerful than projection-valued measurements in quantum steering with two-qubit Werner states.


[Phys. Rev. Lett. 132, 250202] Published Mon Jun 17, 2024

Categories: Journals, Physics

Universal Measurement-Based Quantum Computation in a One-Dimensional Architecture Enabled by Dual-Unitary Circuits

Author(s): David T. Stephen, Wen Wei Ho, Tzu-Chieh Wei, Robert Raussendorf, and Ruben Verresen

A powerful tool emerging from the study of many-body quantum dynamics is that of dual-unitary circuits, which are unitary even when read “sideways,” i.e., along the spatial direction. Here, we show that this provides the ideal framework to understand and expand on the notion of measurement-based qua…


[Phys. Rev. Lett. 132, 250601] Published Mon Jun 17, 2024

Categories: Journals, Physics

Near-Optimal Performance of Quantum Error Correction Codes

Author(s): Guo Zheng, Wenhao He, Gideon Lee, and Liang Jiang

The Knill-Laflamme conditions distinguish exact quantum error correction codes, and they have played a critical role in the discovery of state-of-the-art codes. However, the family of exact codes is a very restrictive one and does not necessarily contain the best-performing codes. Therefore, it is d…


[Phys. Rev. Lett. 132, 250602] Published Mon Jun 17, 2024

Categories: Journals, Physics

Manipulation of tunable nonreciprocal entanglement and one-way steering induced by two-photon driving

PRA: Quantum information - Mon, 2024-06-17 12:00

Author(s): Si-Yu Guan, Hong-Fu Wang, and Xuexi Yi

We consider an all-optical system consisting of two whispering-gallery-mode microring resonators and two adjacent optical waveguides. Pumping fields from different directions can simultaneously excite both clockwise and counterclockwise modes in the two resonators. When the propagation direction of …


[Phys. Rev. A 109, 062423] Published Mon Jun 17, 2024

Categories: Journals, Physics

Power of Sequential Protocols in Hidden Quantum Channel Discrimination

Author(s): Sho Sugiura, Arkopal Dutt, William J. Munro, Sina Zeytinoğlu, and Isaac L. Chuang

In many natural and engineered systems, unknown quantum channels act on a subsystem that cannot be directly controlled and measured, but is instead learned through a controllable subsystem that weakly interacts with it. We study quantum channel discrimination (QCD) under these restrictions, which we…


[Phys. Rev. Lett. 132, 240805] Published Fri Jun 14, 2024

Categories: Journals, Physics

Scalable algorithms for calculating power functions of random quantum states in the noisy intermediate-scale quantum era

PRA: Quantum information - Fri, 2024-06-14 12:00

Author(s): Ruyu Yang, Wencheng Zhao, and Tingting Chen

This article focuses on the development of scalable and qubit-efficient algorithms for computing power functions of random quantum states. Two algorithms, based on the Hadamard Test and Gate Set Tomography, are proposed. We provide a comparative analysis of their computational outcomes, accompanied …


[Phys. Rev. A 109, 062421] Published Fri Jun 14, 2024

Categories: Journals, Physics
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