Journals

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

Exploring thermal equilibria of the Fermi-Hubbard model with variational quantum algorithms

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

Author(s): Jack Y. Araz, Michael Spannowsky, and Matthew Wingate

This study investigates the thermal properties of the repulsive Fermi-Hubbard model with chemical potential using variational quantum algorithms, crucial in comprehending particle behavior within lattices at high temperatures in condensed matter systems. Conventional computational methods encounter …


[Phys. Rev. A 109, 062422] Published Fri Jun 14, 2024

Categories: Journals, Physics

Classical-Nonclassical Polarity of Gaussian States

Author(s): Jiru Liu, Wenchao Ge, and M. Suhail Zubairy

Gaussian states with nonclassical properties such as squeezing and entanglement serve as crucial resources for quantum information processing. Accurately quantifying these properties within multimode Gaussian states has posed some challenges. To address this, we introduce a unified quantification: t…


[Phys. Rev. Lett. 132, 240201] Published Thu Jun 13, 2024

Categories: Journals, Physics

Noncompletely Positive Quantum Maps Enable Efficient Local Energy Extraction in Batteries

Author(s): Aparajita Bhattacharyya, Kornikar Sen, and Ujjwal Sen

Energy extraction from quantum batteries by means of completely positive trace-preserving (CPTP) maps leads to the concept of CPTP-local passive states, which identify bipartite states from which no energy can be squeezed out by applying any CPTP map to a particular subsystem. We prove, for arbitrar…


[Phys. Rev. Lett. 132, 240401] Published Thu Jun 13, 2024

Categories: Journals, Physics

Entanglement Structure and Information Protection in Noisy Hybrid Quantum Circuits

Author(s): Shuo Liu, Ming-Rui Li, Shi-Xin Zhang, and Shao-Kai Jian

In the context of measurement-induced entanglement phase transitions, the influence of quantum noises, which are inherent in real physical systems, is of great importance and experimental relevance. In this Letter, we present a comprehensive theoretical analysis of the effects of both temporally unc…


[Phys. Rev. Lett. 132, 240402] Published Thu Jun 13, 2024

Categories: Journals, Physics

Efficient Quantum Algorithms for Stabilizer Entropies

Author(s): Tobias Haug, Soovin Lee, and M. S. Kim

Stabilizer entropies (SEs) are measures of nonstabilizerness or “magic” that quantify the degree to which a state is described by stabilizers. SEs are especially interesting due to their connections to scrambling, localization and property testing. However, applications have been limited so far as p…


[Phys. Rev. Lett. 132, 240602] Published Thu Jun 13, 2024

Categories: Journals, Physics

Quantum State Tomography via Nonconvex Riemannian Gradient Descent

Author(s): Ming-Chien Hsu, En-Jui Kuo, Wei-Hsuan Yu, Jian-Feng Cai, and Min-Hsiu Hsieh

The recovery of an unknown density matrix of large size requires huge computational resources. State-of-the-art performance has recently been achieved with the factored gradient descent (FGD) algorithm and its variants since they are able to mitigate the dimensionality barrier by utilizing some of t…


[Phys. Rev. Lett. 132, 240804] Published Thu Jun 13, 2024

Categories: Journals, Physics

Information carried by a single particle in quantum multiple-access channels

PRA: Quantum information - Thu, 2024-06-13 12:00

Author(s): Xinan Chen, Yujie Zhang, Andreas Winter, Virginia O. Lorenz, and Eric Chitambar

Nonclassical features of quantum systems have the potential to strengthen the way we currently exchange information. In this paper, we explore this enhancement on the most basic level of single particles. To be more precise, we compare how well multiparty information can be transmitted to a single r…


[Phys. Rev. A 109, 062420] Published Thu Jun 13, 2024

Categories: Journals, Physics

Identification of a natural fieldlike entanglement resource in trapped-ion chains

PRA: Quantum information - Thu, 2024-06-13 12:00

Author(s): Natalie Klco and D. H. Beck

The electromagnetic trapping of ion chains can be regarded as a process of nontrivial entangled quantum state preparation within Hilbert spaces of the local axial motional modes. To begin uncovering properties of this entanglement resource produced as a by-product of conventional ion-trap quantum in…


[Phys. Rev. A 109, 062419] Published Thu Jun 13, 2024

Categories: Journals, Physics

Self-Consistent Many-Body Metrology

Author(s): Jae-Gyun Baak and Uwe R. Fischer

We investigate the classical and quantum metrology of performing parameter estimation with interacting trapped bosons, which we theoretically treat by a self-consistent many-body approach of the multiconfigurational Hartree type. Focusing on a tilted double-well geometry, we compare a self-consisten…


[Phys. Rev. Lett. 132, 240803] Published Wed Jun 12, 2024

Categories: Journals, Physics

User-friendly confidence regions for quantum state tomography

PRA: Quantum information - Wed, 2024-06-12 12:00

Author(s): Carlos de Gois and Matthias Kleinmann

Quantum state tomography is the standard technique for reconstructing a quantum state from experimental data. In the regime of finite statistics, experimental data cannot give perfect information about the quantum state. A common way to express this limited knowledge is by providing confidence regio…


[Phys. Rev. A 109, 062417] Published Wed Jun 12, 2024

Categories: Journals, Physics
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