QUROPE Quantum Information Processing and Communication in Europe

Author(s): Ze Wu, Ping Wang, Tianyun Wang, Yuchen Li, Ran Liu, Yuquan Chen, Xinhua Peng, and Ren-Bao Liu

Correlations of fluctuations are essential to understanding many-body systems and key information for advancing quantum technologies. To fully describe the dynamics of a physical system, all time-ordered correlations (TOCs), i.e., the dynamics-complete set of correlations are needed. The current mea…

[Phys. Rev. Lett. 132, 200802] Published Thu May 16, 2024

Author(s): Charles Day

A deep-sea sponge’s intricate skeleton converts the horizontal flow of ocean currents into a vertical flow through the sponge’s body—a mechanism that helps with the sponge’s filter feeding.

[Physics 17, 81] Published Thu May 16, 2024

Author(s): Faidon Andreadakis, Emanuel Dallas, and Paolo Zanardi

Much recent work has been devoted to the study of information scrambling in quantum systems. In this paper, we study the long-time properties of the algebraic out-of-time-order-correlator (“A−OTOC”) and derive an analytical expression for its long-time average under the nonresonance condition. The A…

[Phys. Rev. A 109, 052424] Published Wed May 15, 2024

Author(s): Nikita A. Zemlevskiy, Henry F. Froland, and Stephan Caspar

A method for analyzing uncertainties in so-called analog quantum simulations could help scientists make precise predictions using these models.

[Phys. Rev. A 109, 052425] Published Wed May 15, 2024

Author(s): Jiaxin Li, Hongmei Yao, Shao-Ming Fei, Zhaobing Fan, and Haitao Ma

We provide a class of positive and trace-preserving maps based on symmetric measurements. From these positive maps we present separability criteria, entanglement witnesses, and the lower bounds of concurrence. We show by detailed examples that our separability criteria, entanglement witnesses, and l…

[Phys. Rev. A 109, 052426] Published Wed May 15, 2024

Author(s): Craig S. Hamilton and Igor Jex

Boson sampling has emerged as an important tool to demonstrate the difference between quantum and classical computers and has attracted the interest of experimentalists and theoreticians. In this work we study boson sampling from general, single-mode states using a scheme that can generate any such …

[Phys. Rev. A 109, 052427] Published Wed May 15, 2024

Author(s): Ryan Wilkinson

A method for analyzing uncertainties in so-called analog quantum simulations could help scientists make precise predictions using these models.

[Physics 17, s51] Published Wed May 15, 2024

Author(s): Qiang Miao and Thomas Barthel

Strongly correlated quantum many-body systems from condensed matter and particle physics are very hard to study classically and variational quantum algorithms (VQAs) may be hampered by barren plateaus, where energy gradients decay exponentially in the system size. The authors prove that this critical problem can be resolved by employing VQAs based on suitable isometric tensor network states, establishing a new route for the investigation of strongly correlated quantum matter on NISQ devices.

[Phys. Rev. A 109, L050402] Published Tue May 14, 2024

Author(s): Kaixiang Su, Nayan Myerson-Jain, Chong Wang, Chao-Ming Jian, and Cenke Xu

We aim to address the following question: if we start with a quantum state with a spontaneously broken higher-form symmetry, what is the fate of the system under weak local quantum measurements? We demonstrate that under certain conditions, a phase transition can be driven by weak measurements, whic…

[Phys. Rev. Lett. 132, 200402] Published Tue May 14, 2024

Author(s): Yuan Li, Lin Cao, Wei Luo, Hui Zhang, Hong Cai, Muhammad Faeyz Karim, Feng Gao, Joseph Fitzsimons, Qinghua Song, and Ai-Qun Liu

Quantum fully homomorphic encryption is shown to be feasible on a compact silicon photonic chip, improving the prospects of a scalable, programmable, and stable quantum network infrastructure.

[Phys. Rev. Lett. 132, 200801] Published Tue May 14, 2024

Author(s): Zhifei Li and Daiqin Su

Concatenation of a bosonic code with a qubit code is one of the promising ways to achieve fault-tolerant quantum computation. As one of the most important bosonic codes, the Gottesman-Kitaev-Preskill (GKP) code is proposed to correct small displacement errors in phase space. If the noise in phase sp…

[Phys. Rev. A 109, 052420] Published Mon May 13, 2024

Author(s): Edoardo Centofanti, Paolo Perinotti, and Alessandro Bisio

We present a fermionic cellular automaton model which describes massless Dirac fermions in 1+1 dimension coupled with local, number preserving interaction. The diagonalization of the two particle sector shows that specific values of the total momentum and of the coupling constant allow for the forma…

[Phys. Rev. A 109, 052421] Published Mon May 13, 2024

Author(s): Xiao-Fan Zhen, Mao-Sheng Li, and Hui-Juan Zuo

Strong nonlocality, proposed by Halder et al. [Phys. Rev. Lett. 122, 040403 (2019)], is a stronger manifestation than quantum nonlocality. Subsequently, Shi et al. presented the concept of the strongest nonlocality [Quantum 6, 619 (2022)]. Recently, Li and Wang [Quantum 7, 1101 (2023)] posed the con…

[Phys. Rev. A 109, 052422] Published Mon May 13, 2024

Author(s): Naoki Mitsuda, Tatsuhiro Ichimura, Kouhei Nakaji, Yohichi Suzuki, Tomoki Tanaka, Rudy Raymond, Hiroyuki Tezuka, Tamiya Onodera, and Naoki Yamamoto

Quantum computing has a potential to accelerate data processing efficiency, especially in machine learning, by exploiting special features such as the quantum interference. The major challenge in this application is that, in general, the task of loading a classical data vector into a quantum state r…

[Phys. Rev. A 109, 052423] Published Mon May 13, 2024

Author(s): Chandrashekhar Gaikwad, Daria Kowsari, Carson Brame, Xingrui Song, Haimeng Zhang, Martina Esposito, Arpit Ranadive, Giulio Cappelli, Nicolas Roch, Eli M. Levenson-Falk, and Kater W. Murch

We utilize a superconducting qubit processor to experimentally probe non-Markovian dynamics of an entangled qubit pair. We prepare an entangled state between two qubits and monitor the evolution of entanglement over time as one of the qubits interacts with a small quantum environment consisting of a…

[Phys. Rev. Lett. 132, 200401] Published Mon May 13, 2024

Author(s): Jung Hoon Han

In its superconducting state, an exotic metal harbors charge carriers that appear to have 4 and 6 times the charge of a single electron, suggesting the formation of Cooper-pair “molecules.”

[Physics 17, 80] Published Mon May 13, 2024

Author(s): Charles Day

The ability to store molecules in reconfigurable optical traps could allow researchers to harness the rich physics of molecules in quantum applications.

[Physics 17, s50] Published Mon May 13, 2024

Author(s): Yongdan Yang, Ying Li, Xiaosi Xu, and Xiao Yuan

Estimating the eigenvalue or energy gap of a Hamiltonian H is vital for studying quantum many-body systems. Particularly, many of the problems in quantum chemistry, condensed-matter physics, and nuclear physics investigate the energy gap between two eigenstates. Hence, how to efficiently solve the e…

[Phys. Rev. A 109, 052416] Published Fri May 10, 2024

Author(s): Andrea Rodriguez-Blanco, Farid Shahandeh, and Alejandro Bermudez

Quantum error correction (QEC) exploits redundancy by encoding logical information into multiple physical qubits. In current implementations of QEC, sequences of nonperfect two-qubit entangling gates are used to codify the information redundantly into multipartite entangled states. Also, to extract …

[Phys. Rev. A 109, 052417] Published Fri May 10, 2024

Author(s): Donghoon Ha and Jeong San Kim

We consider the discrimination of bipartite quantum states and establish a relation between a nonlocal quantum state ensemble and quantum data-hiding processing. Using a bound on the optimal local discrimination of bipartite quantum states, we provide a sufficient condition for a bipartite quantum s…

[Phys. Rev. A 109, 052418] Published Fri May 10, 2024