QUROPE Quantum Information Processing and Communication in Europe

Author(s): Gerard J. Machado, Lluc Sendra, Adam Vallés, and Juan P. Torres

We consider an interferometer based on the concept of induced coherence, where two photons that originate in different second-order nonlinear crystals can interfere. We derive a complementarity relationship that links the first-order coherence between the two interfering photons with a parameter tha…

[Phys. Rev. A 110, 012421] Published Mon Jul 08, 2024

Author(s): Qisheng Wang and Zhicheng Zhang

Since Harrow et al. [A. W. Harrow, A. Hassidim, and S. Lloyd, Phys. Rev. Lett. 103, 150502 (2009)] showed that a system of linear equations with N variables and condition number κ can be solved on a quantum computer in poly[log(N),κ] time, exponentially faster than any classical algorithms, its impr…

[Phys. Rev. A 110, 012422] Published Mon Jul 08, 2024

Author(s): Z.-H. Huang, Y.-F. Jiao, L.-L. Yan, D.-Y. Wang, S.-L. Su, and Hui Jing

The entanglement of different macroscopic objects can provide crucial resources for various quantum applications and quantum-enabled devices. The generation, manipulation, and enhancement of entanglement are pivotal areas of research. In this study, we introduce an approach for producing enhanced no…

[Phys. Rev. A 110, 012423] Published Mon Jul 08, 2024

Author(s): Farha Yasmin and Jan Sperling

Research in quantum information science aims to surpass the scaling limitations of classical information processing. From a physicist's perspective, performance improvement involves a physical speedup in the quantum domain, achieved by dynamically exploiting quantum correlations. In this study, spee…

[Phys. Rev. A 110, 012424] Published Mon Jul 08, 2024

Author(s): Allan Tosta, Antônio C. Lourenço, Daniel Brod, Fernando Iemini, and Tiago Debarba

Particles with exotic statistics serve as an important testbed for quantum information protocols and help us better understand the properties of the more naturally occurring bosons and fermions. The authors investigate the separability of a class of exotic particles known as fermionic anyons, establishing a connection between their capabilities as an architecture for quantum computation and their link with bosonic and fermionic quantum computer setups.

[Phys. Rev. A 110, L010404] Published Mon Jul 08, 2024

Author(s): Séverine Atis

An experiment uncovers the role played by gravity in Ostwald ripening, a spontaneous thermodynamic process responsible for many effects such as the recrystallization of ice cream.

[Physics 17, 104] Published Wed Jul 03, 2024

Author(s): Kevin Randles and S. J. van Enk

We consider two memory nodes of a quantum network connected by flying qubits. We are particularly interested in the case where a flying qubit produced by one node has to be transformed before it can interface efficiently with the next node. Such transformations can be utilized as a key part of the d…

[Phys. Rev. A 110, 012415] Published Wed Jul 03, 2024

Author(s): Xiaozhen Ge, Lijun Liu, Yong Wang, Yu Xiang, Guofeng Zhang, Li Li, and Shuming Cheng

The authors present a geometric picture for tripartite entanglement that is valid for discrete, continuous, and even hybrid quantum systems. They further show that the triangle area, enclosed by any tripartite state, is a faithful measure for genuine tripartite entanglement.

[Phys. Rev. A 110, L010402] Published Wed Jul 03, 2024

Author(s): Na Wang, Meihong Wang, and Xiaolong Su

Entanglement swapping, which establishes entanglement between two independent and distant entangled states, is a key element of a quantum repeater in an entanglement-based quantum network. In continuous-variable (CV) entanglement swapping, it is essential to enhance the entanglement of entanglement …

[Phys. Rev. A 110, 012416] Published Wed Jul 03, 2024

Author(s): Ranendu Adhikary, Abhishek Mishra, and Ramij Rahaman

Self-testing of quantum correlations is an important problem in quantum information theory, and the task becomes more challenging in multipartite scenarios. In this context, the authors provide a network-assistance-free self-testing scheme for genuine multipartite entangled states by employing a generalized Hardy-type nonlocality argument and exploring its device-independent bound of the maximum probability of success.

[Phys. Rev. A 110, L010401] Published Wed Jul 03, 2024

Author(s): Victor Barizien and Jean-Daniel Bancal

It is well known that the set of statistics that can be observed in a Bell-type experiment is limited by quantum theory. Unfortunately, tools are missing to identify the precise boundary of this set. Here, we propose to study the set of quantum statistics from a dual perspective. By considering all …

[Phys. Rev. Lett. 133, 010201] Published Tue Jul 02, 2024

Author(s): Chengkai Zhu, Zhiping Liu, Chenghong Zhu, and Xin Wang

In the realm of fault-tolerant quantum computing, stabilizer operations play a pivotal role, characterized by their remarkable efficiency in classical simulation. This efficiency sets them apart from nonstabilizer operations within the quantum computational theory. In this Letter, we investigate the…

[Phys. Rev. Lett. 133, 010202] Published Tue Jul 02, 2024

Author(s): Hongzheng Zhao, Marin Bukov, Markus Heyl, and Roderich Moessner

Digital quantum simulation relies on Trotterization to discretize time evolution into elementary quantum gates. On current quantum processors with notable gate imperfections, there is a critical trade-off between improved accuracy for finer time steps, and increased error rate on account of the larg…

[Phys. Rev. Lett. 133, 010603] Published Tue Jul 02, 2024

Author(s): Rachel Berkowitz

Researchers have made the most precise measurement to date of the excited nuclear state of thorium-229, a candidate isotope for an ultraprecise nuclear clock.

[Physics 17, s75] Published Tue Jul 02, 2024

Author(s): Rui Zhang, Wenkui Ding, Zhucheng Zhang, Lei Shao, Yuyu Zhang, and Xiaoguang Wang

There is a prevalent effort to achieve quantum-enhanced metrology using criticality. However, the extent to which estimation precision is enhanced through criticality still needs further exploration under the constraint of finite time resources. We clarify relations between quantum metrology and cri…

[Phys. Rev. A 110, 012413] Published Tue Jul 02, 2024

Author(s): Colin Rylands, Katja Klobas, Filiberto Ares, Pasquale Calabrese, Sara Murciano, and Bruno Bertini

In the Mpemba effect, a warm liquid freezes faster than a cold one. Three studies investigate quantum versions of this effect, challenging our understanding of quantum thermodynamics.

[Phys. Rev. Lett. 133, 010401] Published Mon Jul 01, 2024

Author(s): Lata Kh. Joshi, Johannes Franke, Aniket Rath, Filiberto Ares, Sara Murciano, Florian Kranzl, Rainer Blatt, Peter Zoller, Benoît Vermersch, Pasquale Calabrese, Christian F. Roos, and Manoj K. Joshi

In the Mpemba effect, a warm liquid freezes faster than a cold one. Three studies investigate quantum versions of this effect, challenging our understanding of quantum thermodynamics.

[Phys. Rev. Lett. 133, 010402] Published Mon Jul 01, 2024

Author(s): Shahaf Aharony Shapira, Yotam Shapira, Jovan Markov, Gianluca Teza, Nitzan Akerman, Oren Raz, and Roee Ozeri

In the Mpemba effect, a warm liquid freezes faster than a cold one. Three studies investigate quantum versions of this effect, challenging our understanding of quantum thermodynamics.

[Phys. Rev. Lett. 133, 010403] Published Mon Jul 01, 2024

Author(s): Poetri Sonya Tarabunga, Emanuele Tirrito, Mari Carmen Bañuls, and Marcello Dalmonte

Nonstabilizerness, also known as “magic,” stands as a crucial resource for achieving a potential advantage in quantum computing. Its connection to many-body physical phenomena is poorly understood at present, mostly due to a lack of practical methods to compute it at large scales. We present a novel…

[Phys. Rev. Lett. 133, 010601] Published Mon Jul 01, 2024

Author(s): Guglielmo Lami and Mario Collura

We present a novel classical algorithm designed to learn the stabilizer group—namely, the group of Pauli strings for which a state is a ±1 eigenvector—of a given matrix product state (MPS). The algorithm is based on a clever and theoretically grounded biased sampling in the Pauli (or Bell) basis. It…

[Phys. Rev. Lett. 133, 010602] Published Mon Jul 01, 2024