QUROPE Quantum Information Processing and Communication in Europe

Author(s): Michael Schirber

A liquid-like spreading of metal atoms on a topological material can generate a superconductor—one that might benefit quantum computing.

[Physics 17, 100] Published Fri Jun 21, 2024

Author(s): Ryan Wilkinson

A simple model based on network theory can reproduce the complex structures seen in urban transportation networks.

[Physics 17, s70] Published Fri Jun 21, 2024

Author(s): Robert Garisto

Theorists explain why cosmic inflation might appear to be driven by a single inflaton field, even if it had actually been driven by two or more such fields.

[Physics 17, s78] Published Fri Jun 21, 2024

Author(s): David R. M. Arvidsson-Shukur, Crispin H. W. Barnes, Hugo V. Lepage, Seth Lloyd, Noah Lupu-Gladstein, Wilfred Salmon, and Flavio Salvati

In a recent paper [Das, Modak, and Bera, Phys. Rev. A 107, 042413 (2023)], Das et al. claim that Kirkwood-Dirac negativity is not required to achieve anomalous values of the quantum Fisher information encoded in postselected (filtered) particles. We argue that this claim is wrong. Further, we show t…

[Phys. Rev. A 109, 066401] Published Fri Jun 21, 2024

Author(s): Sourav Das, Subhrajit Modak, and Manabendra Nath Bera

In Das et al. [Phys. Rev. A 107, 042413 (2023)], we showed that Kirkwood-Dirac negativity is not necessary to achieve anomalous quantum Fisher information. Arvidsson-Shukur et al. [preceding Comment, Phys. Rev. A (to be published)] claim that one of our conclusions is wrong. Here, we argue that the …

[Phys. Rev. A 109, 066402] Published Fri Jun 21, 2024

Author(s): Liubov Markovich, Savvas Malikis, Stefano Polla, and Jordi Tura

Parameter shift rules enable the estimation of the derivatives of expectation values with respect to the dynamical evolution of a state. Thus, they provide a valuable tool in variational optimization and insight into the dynamical behavior of quantum systems. Constructing parameter shift rules appli…

[Phys. Rev. A 109, 062429] Published Fri Jun 21, 2024

Author(s): Kangyuan Yi, Yong-Ju Hai, Kai Luo, Ji Chu, Libo Zhang, Yuxuan Zhou, Yao Song, Song Liu, Tongxing Yan, Xiu-Hao Deng, Yuanzhen Chen, and Dapeng Yu

As quantum circuits become more integrated and complex, additional error sources that were previously insignificant start to emerge. Consequently, the fidelity of quantum gates benchmarked under pristine conditions falls short of predicting their performance in realistic circuits. To overcome this p…

[Phys. Rev. Lett. 132, 250604] Published Thu Jun 20, 2024

Author(s): Ke Zeng, Xiaohui Yu, Martin B. Plenio, and Zhen-Yu Wang

We present a quantum sensing technique that utilizes a sequence of π pulses to cyclically drive the qubit dynamics along a geodesic path of adiabatic evolution. This approach effectively suppresses the effects of both decoherence noise and control errors while simultaneously removing unwanted resona…

[Phys. Rev. Lett. 132, 250801] Published Thu Jun 20, 2024

Author(s): Marric Stephens

Researchers have measured a hard-to-observe electronic transition in strontium that was predicted six decades ago.

[Physics 17, s72] Published Thu Jun 20, 2024

Author(s): Xue Yang, Yan-Han Yang, Shao-Ming Fei, and Ming-Xing Luo

The presence of quantum multipartite entanglement implies the existence of a thermodynamic quantity known as the ergotropic gap, which is defined as the difference between the maximal global and local extractable works from the system. We establish a direct relation between the geometric measure of …

[Phys. Rev. A 109, 062427] Published Thu Jun 20, 2024

Author(s): Yin Mo, Chengkai Zhu, Zhiping Liu, Mingrui Jing, and Xin Wang

In quantum computing, the nonstabilizerness of quantum operations is crucial for understanding and quantifying quantum speedups. In this study, we explore the phenomena of nonstabilizerness of the quantum SWITCH, a novel structure that allows quantum states to pass through operations in a superposit…

[Phys. Rev. A 109, 062428] Published Thu Jun 20, 2024

Author(s): Toshiaki Kanai, Dafei Jin, and Wei Guo

Single electrons trapped on solid-neon surfaces have recently emerged as a promising platform for charge qubits. Experimental results have revealed their exceptionally long coherence times, yet the actual quantum states of these trapped electrons, presumably on imperfectly flat neon surfaces, remain…

[Phys. Rev. Lett. 132, 250603] Published Tue Jun 18, 2024

Author(s): Rachel Berkowitz

Samantha Lawler would like to see more done to reduce the detrimental impact of satellites on dark skies, telescope data, and publicly funded research.

[Physics 17, 97] Published Tue Jun 18, 2024

Author(s): Ryan Wilkinson

Spin currents carried by magnetic waves called magnons can be sent across a device without using insulating magnets—a result that could lead to spintronic devices compatible with silicon electronics.

[Physics 17, s67] Published Tue Jun 18, 2024

Author(s): Ping Li and Yongming Li

Quantum coherence is an intrinsic property within a single quantum system. Many different coherent resource theories have been proposed to characterize this property within the framework of resource theory. This difference is based on the difference in the identification of “free” operations. In thi…

[Phys. Rev. A 109, 062424] Published Tue Jun 18, 2024

Author(s): Mingrui Jing, Geng Liu, Hongbin Ren, and Xin Wang

Learning probability distribution is an essential framework in classical learning theory. As a counterpart, quantum state learning has spurred the exploration of quantum machine learning theory. However, as dimensionality increases, learning a high-dimensional unknown quantum state via conventional …

[Phys. Rev. A 109, 062425] Published Tue Jun 18, 2024

Author(s): Abhi Kumar Sharma and Shayan Srinivasa Garani

Magic-state distillation is a protocol to purify noisy quantum states using quantum stabilizer codes. In this paper, we provide conditions for identifying magic states along with analytical expressions for computing the noise threshold. Through quantum entropic results, we prove the convergence of t…

[Phys. Rev. A 109, 062426] Published Tue Jun 18, 2024

Author(s): Kristian Piscicchia, Sandro Donadi, Simone Manti, Angelo Bassi, Maaneli Derakhshani, Lajos Diósi, and Catalina Curceanu

In this work the spontaneous electromagnetic radiation from atomic systems, induced by dynamical wave-function collapse, is investigated in the x-ray domain. Strong departures are evidenced with respect to the simple cases considered until now in the literature, in which the emission is either perfe…

[Phys. Rev. Lett. 132, 250203] Published Tue Jun 18, 2024

Author(s): Sai Li, De-Jian Pan, Yuan-Ke Zhu, Jia-Lang Zhou, Wen-Cui Liao, Wei-Xin Zhang, Zhen-Tao Liang, Qing-Xian Lv, Haifeng Yu, Zheng-Yuan Xue, Hui Yan, and Shi-Liang Zhu

The Hamiltonian, which determines the evolution of a quantum system, is fundamental in quantum physics. Therefore, it is crucial to implement high-precision generation and measurement of the Hamiltonian in a practical quantum system. Here, we experimentally demonstrate ultrahigh-precision Hamiltonia…

[Phys. Rev. Lett. 132, 250204] Published Tue Jun 18, 2024

Author(s): Mykyta Onizhuk, Yu-Xin Wang (王语馨), Jonah Nagura, Aashish A. Clerk, and Giulia Galli

We propose a new approach to simulate the decoherence of a central spin coupled to an interacting dissipative spin bath with cluster-correlation expansion techniques. We benchmark the approach on generic 1D and 2D spin baths and find excellent agreement with numerically exact simulations. Our calcul…

[Phys. Rev. Lett. 132, 250401] Published Tue Jun 18, 2024