QUROPE Quantum Information Processing and Communication in Europe

Author(s): Göktuğ Karpat and Barış Çakmak

We examine the emergence of dynamical memory effects in quantum processes having indefinite time direction and causal order. In particular, we focus on the class of phase-covariant qubit channels, which encompasses some of the most significant paradigmatic open quantum system models. In order to ass…

[Phys. Rev. A 110, 012446] Published Thu Jul 18, 2024

Author(s): Tatsuhiko N. Ikeda, Sho Sugiura, and Anatoli Polkovnikov

An external periodic (Floquet) drive is believed to bring any initial state to the featureless infinite temperature state in generic nonintegrable isolated quantum many-body systems in the thermodynamic limit, irrespective of the driving frequency Ω. However, numerical or analytical evidence either …

[Phys. Rev. Lett. 133, 030401] Published Wed Jul 17, 2024

Author(s): Eric Kubischta and Ian Teixeira

We introduce twisted unitary t-groups, a generalization of unitary t-groups under a twisting by an irreducible representation. We then apply representation theoretic methods to the Knill-Laflamme error correction conditions to show that twisted unitary t-groups automatically correspond to quantum co…

[Phys. Rev. Lett. 133, 030602] Published Wed Jul 17, 2024

Author(s): Charles Day

The pressures at which some elements start superconducting are so high that making detailed measurements of the transition has been impossible—until now.

[Physics 17, s84] Published Wed Jul 17, 2024

Author(s): Rajdeep Paul, Souradeep Sasmal, and A. K. Pan

Self-testing protocols refer to novel device-independent certification schemes wherein the devices are uncharacterized and the dimension of the system remains unspecified. The optimal quantum violation of Bell's inequality facilitates such self-testing. In this work we put forth a protocol for self-…

[Phys. Rev. A 110, 012444] Published Wed Jul 17, 2024

Author(s): Ivan Medina, Alexandre Drinko, Guilherme I. Correr, Pedro C. Azado, and Diogo O. Soares-Pinto

The energy extraction from quantum sources is a key task to develop new quantum devices such as quantum batteries (QB). In this context, one of the main figures of merit is the ergotropy, which measures the maximal amount of energy (as work) that can be extracted from the quantum source by means of …

[Phys. Rev. A 110, 012443] Published Wed Jul 17, 2024

Author(s): Simon Lieu, Yu-Jie Liu, and Alexey V. Gorshkov

An interesting problem in the field of quantum error correction involves finding a physical system that hosts a “passively protected quantum memory,” defined as an encoded qubit coupled to an environment that naturally wants to correct errors. To date, a quantum memory stable against finite-temperat…

[Phys. Rev. Lett. 133, 030601] Published Tue Jul 16, 2024

Author(s): Charles Day

Using a detailed simulation, researchers reveal how climate change will affect the regional dynamics of the conveyor-belt-like circulation of water through the Atlantic Ocean.

[Physics 17, 115] Published Tue Jul 16, 2024

Author(s): Agnese Curatolo

Pebbles that are slightly curved—rather than completely flat—exert the highest impact forces when dropped onto a watery surface.

[Physics 17, s85] Published Tue Jul 16, 2024

Author(s): Eyal Buks

Multistability is experimentally observed in a variety of quantum systems but cannot be derived from any theoretical model that is based on a monostable master equation. The author investigates the relation between disentanglement and multistability in the few-spin transverse Ising model and finds that multistability can be obtained in the presence of spontaneous disentanglement.

[Phys. Rev. A 110, 012439] Published Mon Jul 15, 2024

Author(s): Katarzyna Siudzińska

We use symmetric measurement operators to construct quantum channels that provide a further generalization of generalized Pauli channels. The resulting maps are bistochastic but, in general, no longer mixed unitary. We analyze their important properties, such as complete positivity and the ability t…

[Phys. Rev. A 110, 012440] Published Mon Jul 15, 2024

Author(s): Ming Yang, Dongkai Zhang, and Lixiang Chen

Recent advancements have expanded Hardy's nonlocality arguments into multisetting and multidimensional systems to enhance quantum correlations. In comparison with Hardy's nonlocality argument, Cabello's nonlocality argument (CNA) emerges as a superior choice for illustrating nonlocal features. An op…

[Phys. Rev. A 110, 012441] Published Mon Jul 15, 2024

Author(s): Zi-Jian Xu and Jun-Hong An

Permitting the transmission of unknown quantum states over long distances by using entanglement, quantum teleportation serves as an important building block for many quantum technologies. However, in the noisy intermediate-scale quantum era, the practical realization of quantum teleportation is inev…

[Phys. Rev. A 110, 012442] Published Mon Jul 15, 2024

Author(s): Naoki Masuda

A machine-learning framework predicts when a complex system, such as an ecosystem or a power grid, will undergo a critical transition.

[Physics 17, 110] Published Mon Jul 15, 2024

Author(s): Hui-Nan Wu, Yu-Huai Li, Bo Li, Xiang You, Run-Ze Liu, Ji-Gang Ren, Juan Yin, Chao-Yang Lu, Yuan Cao, Cheng-Zhi Peng, and Jian-Wei Pan

The emergence of quantum mechanics and general relativity has transformed our understanding of the natural world significantly. However, integrating these two theories presents immense challenges, and their interplay remains untested. Recent theoretical studies suggest that the single-photon interfe…

[Phys. Rev. Lett. 133, 020201] Published Fri Jul 12, 2024

Author(s): Michael Schirber

Experiments on a bed of plastic beads reveal a temperature-dependent stiffening over time, which appears to be related to molecular-scale deformations.

[Physics 17, 112] Published Fri Jul 12, 2024

Author(s): Julie Gould

Sonification and other multisensorial approaches offer powerful tools to analyze data, help visually impaired researchers, communicate science, and create science-inspired art.

[Physics 17, 113] Published Fri Jul 12, 2024

Author(s): M. Yassine Naghmouchi and Wesley da Silva Coelho

This paper presents a hybrid classical-quantum approach to solve mixed-integer linear programming (MILP) using neutral-atom quantum computations. We apply Benders decomposition (BD) to segment MILPs into a master problem (MP) and a subproblem, where the MP is addressed using a neutral-atom device, a…

[Phys. Rev. A 110, 012434] Published Fri Jul 12, 2024

Author(s): Ashutosh Goswami, Mehdi Mhalla, and Valentin Savin

A fault-tolerant way to prepare logical code states of Q1 codes, i.e., quantum polar codes encoding one qubit, was recently proposed. The fault tolerance therein is guaranteed by an error detection gadget, where, if an error is detected during the preparation, one entirely discards the preparation. …

[Phys. Rev. A 110, 012438] Published Fri Jul 12, 2024

Author(s): Steven Herbert, Julien Sorci, and Yao Tang

We give an explicit construction to perform any n-qubit computational-basis-state transposition using Θ(n) gates. This nearly coincides with the lower bound Ω[n/log(nd)] on worst-case and average-case gate complexities to perform transpositions using a d-element gate set, which we also prove.

[Phys. Rev. A 110, 012437] Published Fri Jul 12, 2024