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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

Mimicking an Elephant Trunk

APS Physics - Fri, 2024-06-14 12:00

Author(s): Philip Ball

The extraordinary range of motions achieved by elephants’ trunks can be mimicked by a physical model that uses just three “muscles,” which could inspire robotic designs.


[Physics 17, 98] Published Fri Jun 14, 2024

Categories: 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

Gravitational-Wave Memory May Illustrate Spacetime Symmetries

APS Physics - Thu, 2024-06-13 12:00

Author(s): Elizabeth Fernandez

Observing gravitational-wave memory may help physicists test general relativity predictions about large-scale symmetries in the fabric of spacetime.


[Physics 17, 95] Published Thu Jun 13, 2024

Categories: Physics

Adding Certainty to Plutonium’s Fission Yield

APS Physics - Thu, 2024-06-13 12:00

Author(s): Rachel Berkowitz

A first-of-its-kind measurement reveals the energy spectrum of the neutrons produced during the fission of plutonium, a common nuclear fuel component.


[Physics 17, s68] Published Thu Jun 13, 2024

Categories: 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

A Step toward Quantum Gases of Doubly Polar Molecules

APS Physics - Wed, 2024-06-12 12:00

Author(s): David Ehrenstein

Researchers created an ultracold gas of molecules with strong magnetic dipoles, which may lead to new types of Bose-Einstein condensates.


[Physics 17, s73] Published Wed Jun 12, 2024

Categories: 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

Reexamination of quantum state transformations with zero communication

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

Author(s): Ian George and Eric Chitambar

It is known that general convertibility of bipartite entangled states is not possible to arbitrary error without some classical communication. While some tradeoffs between communication cost and conversion error have been proven, these bounds can be very loose. In particular, there are many cases in…


[Phys. Rev. A 109, 062418] Published Wed Jun 12, 2024

Categories: Journals, Physics

Partial-transpose-guided entanglement classes and minimum noise filtering in many-body Gaussian quantum systems

PRA: Quantum information - Tue, 2024-06-11 12:00

Author(s): Boyu Gao and Natalie Klco

The reduction and distortion of quantum correlations in the presence of classical noise leads to varied levels of inefficiency in the availability of entanglement as a resource for quantum information processing protocols. While generically minimizing required entanglement for mixed quantum states r…


[Phys. Rev. A 109, 062413] Published Tue Jun 11, 2024

Categories: Journals, Physics

Quantum control for the Zeno effect with noise

PRA: Quantum information - Tue, 2024-06-11 12:00

Author(s): Haorui Chen and Shengshi Pang

The quantum Zeno effect is a distinctive phenomenon in quantum mechanics, describing the nontrivial effect of frequent projective measurements on hindering the evolution of a quantum system. However, when subjected to environmental noise, the quantum system may dissipate, and the quantum Zeno effect…


[Phys. Rev. A 109, 062414] Published Tue Jun 11, 2024

Categories: Journals, Physics

Dual-frame optimization for informationally complete quantum measurements

PRA: Quantum information - Tue, 2024-06-11 12:00

Author(s): Laurin E. Fischer, Timothée Dao, Ivano Tavernelli, and Francesco Tacchino

Randomized measurement protocols such as classical shadows represent powerful resources for quantum technologies, with applications ranging from quantum state characterization and process tomography to machine learning and error mitigation. Recently, the notion of measurement dual frames, in which c…


[Phys. Rev. A 109, 062415] Published Tue Jun 11, 2024

Categories: Journals, Physics
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