QUROPE Quantum Information Processing and Communication in Europe

Author(s): Jicun Li, Fei Shi, and Xiande Zhang

A set of orthogonal states is the strongest nonlocal set if it is locally stable in every bipartition, which shows the strong quantum nonlocality proposed by Halder et al. [Phys. Rev. Lett. 122, 040403 (2019)]. The existence of the strongest nonlocal sets with the minimum size is an open question. I…

[Phys. Rev. A 108, 062407] Published Fri Dec 08, 2023

Author(s): Yanfang Wang, Shibei Xue, Hongbin Song, and Min Jiang

In this paper we propose a non-Markovian quantum channel approach to mitigating the degradation of the average fidelity in continuous-variable quantum teleportation. The non-Markovian quantum channel is modeled by an augmented system where ancillary systems are introduced to represent the internal m…

[Phys. Rev. A 108, 062406] Published Fri Dec 08, 2023

Author(s): Xing-Yan Fan, Zhen-Peng Xu, Jia-Le Miao, Hong-Ye Liu, Yi-Jia Liu, Wei-Min Shang, Jie Zhou, Hui-Xian Meng, Otfried Gühne, and Jing-Ling Chen

Bell inequality is a vital tool to detect the nonlocal correlations, but the construction of it for multipartite systems is still a complicated problem. In this work, inspired via a decomposition of (n+1)-partite Bell inequalities into n-partite ones, we present a generalized iterative formula to co…

[Phys. Rev. A 108, 062404] Published Wed Dec 06, 2023

Author(s): Yaohua Li and Yong-Chun Liu

Quantum entanglement and classical topology are two distinct phenomena that are difficult to be connected together. Here we discover that an open bosonic quadratic chain exhibits topology-induced entanglement effect. When the system is in the topological phase, the edge modes can be entangled in the…

[Phys. Rev. A 108, 062405] Published Wed Dec 06, 2023

Author(s): Lu Wang, Shu-Qian Liu, Feng-lin Wu, Hao Fan, and Si-Yuan Liu

We investigate a series of two-mode quantum batteries (QBs) which exhibits better performance in both the stored energy and average charging power compared to the two-photon case. In both the model related to coupling strength and Raman cases, we find the QBs can store energy faster and have a highe…

[Phys. Rev. A 108, 062402] Published Mon Dec 04, 2023

Author(s): Sumin Lim, Junjie Liu, and Arzhang Ardavan

The authors propose a quantum memory, implemented on a spin-7/2 nucleus coupled to an electron spin-1/2 qubit, which provides X, Y, and Z error correction using fewer quantum resources than the equivalently effective qubit-based protocols.

[Phys. Rev. A 108, 062403] Published Mon Dec 04, 2023

Author(s): Mei-Song Wei, Ming-Jie Liao, Yi-Qing Wang, Zijian Lin, Xingze Qiu, Ce Wang, Jingping Xu, and Yaping Yang

The topological properties of a Heisenberg XY spin model on the square lattice in the form of a two-dimensional Su-Schrieffer-Heeger model is investigated through the quench dynamics. Based on the topological edge states or the higher-order topological corner states of the square lattice, we propose…

[Phys. Rev. A 108, 062401] Published Fri Dec 01, 2023

Author(s): Mir Alimuddin, Ananya Chakraborty, Govind Lal Sidhardh, Ram Krishna Patra, Samrat Sen, Snehasish Roy Chowdhury, Sahil Gopalkrishna Naik, and Manik Banik

Hardy's argument constitutes an elegant proof of quantum nonlocality. In this work, we report an exotic application of Hardy's nonlocal correlations in two-party communication setup. We come up with a task, wherein a positive payoff can be through 1 bit of communication from the sender to the receiv…

[Phys. Rev. A 108, 052430] Published Tue Nov 28, 2023

Author(s): Kornikar Sen, Chirag Srivastava, and Ujjwal Sen

The concept of entanglement witnesses forms a useful technique to detect entanglement in realistic quantum devices. Measurement-device-independent nonlinear entanglement witnesses (MDI-NEWs) are a kind of entanglement witness that eliminates dependence on the correct alignments of measurement device…

[Phys. Rev. A 108, 052426] Published Mon Nov 27, 2023

Author(s): Niclas Götting, Frederik Lohof, and Christopher Gies

Quantum reservoir computing is an emerging field in machine learning with quantum systems. While classical reservoir computing has proven to be a capable concept for enabling machine learning on real, complex dynamical systems with many degrees of freedom, the advantage of its quantum analog has yet…

[Phys. Rev. A 108, 052427] Published Mon Nov 27, 2023

Author(s): Matthew P. Stafford and Nicolas C. Menicucci

Continuous-variable quantum computing architectures based upon the Gottesman-Kitaev-Preskill (GKP) encoding have emerged as a promising candidate because one can achieve fault tolerance with a probabilistic supply of GKP states and Gaussian operations. Furthermore, by generalizing to rectangular-lat…

[Phys. Rev. A 108, 052428] Published Mon Nov 27, 2023

Author(s): A. D. Kodukhov and D. A. Kronberg

The seminal multibeam Young's interference experiment established the wave-particle duality principle, connecting quantum properties (interference) and path information. To quantify this connection, we propose a framework in which quantum measurement is applied to a subsystem of an entangled state, …

[Phys. Rev. A 108, 052429] Published Mon Nov 27, 2023

Author(s): Uthirakalyani G., Anuj K. Nayak, Avhishek Chatterjee, and Lav R. Varshney

Existing lower bounds on redundancy in fault-tolerant quantum circuits are applicable when both the input and the intended output are quantum states. These bounds may not necessarily hold, however, when the intended outputs are classical bits, as in Shor's or Grover's algorithms. Here we show that, …

[Phys. Rev. A 108, 052425] Published Wed Nov 22, 2023

Author(s): Marco Majland, Patrick Ettenhuber, and Nikolaj Thomas Zinner

Quantum chemistry has been identified as one of the most promising areas where quantum computing can have a tremendous impact. For current noisy intermediate-scale quantum (NISQ) devices, one of the best available methods to prepare approximate wave functions on quantum computers is the adaptive der…

[Phys. Rev. A 108, 052422] Published Tue Nov 21, 2023

Author(s): Constantin Dalyac, Louis-Paul Henry, Minhyuk Kim, Jaewook Ahn, and Loïc Henriet

In the past years, many quantum algorithms have been proposed to tackle hard combinatorial problems. In particular, the maximum independent set (MIS) is a known NP-hard problem that can be naturally encoded in Rydberg atom arrays. By representing a graph with an ensemble of neutral atoms one can lev…

[Phys. Rev. A 108, 052423] Published Tue Nov 21, 2023

Author(s): Yi-Jun Luo, Jin-Ming Liu, and Chengjie Zhang

In recent years, supervised and semisupervised machine learning methods such as neural networks, support vector machines (SVMs), and semisupervised support vector machines (S4VMs) have been widely used in quantum entanglement and quantum steering verification problems. However, few studies have focu…

[Phys. Rev. A 108, 052424] Published Tue Nov 21, 2023

Author(s): Niklas Hörnedal and Ole Sönnerborn

Many quantum speed limits for isolated systems can be generalized to also apply to closed systems. This is, for example, the case with the well-known Mandelstam-Tamm quantum speed limit. Margolus and Levitin derived an equally well-known and ostensibly related quantum speed limit, and it seems to be…

[Phys. Rev. A 108, 052421] Published Mon Nov 20, 2023

Author(s): Ilia Khait, Edwin Tham, Dvira Segal, and Aharon Brodutch

The authors show that limited intermodule information exchange in distributed quantum computing architectures can enhance quantum problem solving, as demonstrated with a dual-core variational quantum eigensolver. These results indicate that quantum processors that use modular operations may be viable in the near future.

[Phys. Rev. A 108, L050401] Published Mon Nov 20, 2023

Author(s): Chao-Chao Li, Run-Hong He, and Zhao-Ming Wang

In pursuit of enhancing the prediction capabilities of neural networks, it has been a longstanding objective to create datasets encompassing a diverse array of samples. The purpose is to broaden the horizons of the neural network and continually strive for improved prediction accuracy during the tra…

[Phys. Rev. A 108, 052418] Published Fri Nov 17, 2023

Author(s): Hai-Chau Nguyen

We show that the method of iterative Bayesian unfolding for mitigating readout errors in quantum computers can be derived from an information theoretic analysis. This inspires more flexible applications of this error-mitigation scheme. In particular, we distinguish between structural mitigation and …

[Phys. Rev. A 108, 052419] Published Fri Nov 17, 2023