QUROPE Quantum Information Processing and Communication in Europe

Author(s): Ming-Ming Wang and Xiao-Ying Zhang

Bayesian networks are powerful tools for probabilistic analysis and have been widely used in machine learning and data science. Unlike the time-consuming parameter training process of neural networks, Bayes classifiers constructed on Bayesian networks can make decisions based solely on statistical d…

[Phys. Rev. A 110, 012433] Published Fri Jul 12, 2024

Author(s): Jack Ceroni, Ian MacCormack, and Guillaume Verdon

We provide a rigorous proof of the approximate convergence of sliding-window quantum belief-propagation as outlined heuristically in the work of Bilgin and Poulin [Phys. Rev. B 81, 054106 (2010)], in the absence of the quantum Markov property. In particular, we confirm the hypothesis outlined in thi…

[Phys. Rev. A 110, 012435] Published Fri Jul 12, 2024

Author(s): Kan Takase, Fumiya Hanamura, Hironari Nagayoshi, J. Eli Bourassa, Rafael N. Alexander, Akito Kawasaki, Warit Asavanant, Mamoru Endo, and Akira Furusawa

The generation of a logical qubit called the Gottesman-Kitaev-Preskill (GKP) qubit in an optical traveling wave is a major challenge for realizing large-scale universal fault-tolerant optical quantum computers. Recently, probabilistic generation of elementary GKP qubits has been demonstrated using p…

[Phys. Rev. A 110, 012436] Published Fri Jul 12, 2024

Author(s): Katherine Wright

Observations of seven fast-moving stars at the center of a dense star cluster in the Milky Way reveal the presence of an intermediate-mass black hole, perhaps the most puzzling class of these dark objects.

[Physics 17, 114] Published Thu Jul 11, 2024

Author(s): Nikhil Karthik

Electron neutrinos produced by proton–proton collisions at the LHC have been experimentally observed.

[Physics 17, s80] Published Thu Jul 11, 2024

Author(s): Akshay Seshadri, Martin Ringbauer, Jacob Spainhour, Rainer Blatt, Thomas Monz, and Stephen Becker

As quantum devices become more complex and the requirements on these devices become more demanding, it is crucial to be able to verify the performance of such devices in a scalable and reliable fashion. A cornerstone task in this challenge is quantifying how close an experimentally prepared quantum …

[Phys. Rev. Lett. 133, 020402] Published Wed Jul 10, 2024

Author(s): Christian Bertoni, Jonas Haferkamp, Marcel Hinsche, Marios Ioannou, Jens Eisert, and Hakop Pashayan

We provide practical and powerful schemes for learning properties of a quantum state using a small number of measurements. Specifically, we present a randomized measurement scheme modulated by the depth of a random quantum circuit in one spatial dimension. This scheme interpolates between two known …

[Phys. Rev. Lett. 133, 020602] Published Wed Jul 10, 2024

Author(s): Pingal Pratyush Nath, Debashis Saha, Dipankar Home, and Urbasi Sinha

We theoretically formulate and experimentally demonstrate a secure scheme for semi-device-independent quantum random number generation by utilizing Leggett-Garg inequality violations, within a loophole-free photonic architecture. The quantification of the generated randomness is rigorously estimated…

[Phys. Rev. Lett. 133, 020802] Published Wed Jul 10, 2024

Author(s): Rachel Berkowitz

A statistical tool tests the long-held assumption that small-scale turbulence is isotropic.

[Physics 17, s77] Published Wed Jul 10, 2024

Author(s): Akshay Seshadri, Martin Ringbauer, Jacob Spainhour, Thomas Monz, and Stephen Becker

Estimating the fidelity with a target state is important in quantum information tasks. Many fidelity-estimation techniques present a suitable measurement scheme to perform the estimation. In contrast, we present techniques that allow the experimentalist to choose a convenient measurement setting. Ou…

[Phys. Rev. A 110, 012431] Published Wed Jul 10, 2024

Author(s): Shuyue Wang, Wuji Zhang, Chunfang Sun, Chunfeng Wu, and Gangcheng Wang

In this study we engineer the z component of the Dzyaloshinskii-Moriya interaction mediated by photons to emulate ground-state chiral excitation based on three-level atoms driven by quantum and classical fields. We employ adiabatic elimination techniques to derive an effective Dzyaloshinskii-Moriya …

[Phys. Rev. A 110, 012432] Published Wed Jul 10, 2024

Author(s): Francesco Campaioli, Stefano Gherardini, James Q. Quach, Marco Polini, and Gian Marcello Andolina

Storage of energy in quantum devices is of practical relevance for applications in quantum technologies. The topic attracts attention also of a more foundational character due to the possibility that the charging power and work extraction can benefit from quantum coherence and collective effects. This Colloquium reviews theoretical concepts and experimental implementations of energy storage in quantum batteries drawing on work in quantum thermodynamics and quantum information science.

[Rev. Mod. Phys. 96, 031001] Published Tue Jul 09, 2024

Author(s): Maxwell Aifer, Juzar Thingna, and Sebastian Deffner

Quantum synchronization is crucial for understanding complex dynamics and holds potential applications in quantum computing and communication. Therefore, assessing the thermodynamic resources required for finite-time synchronization in continuous-variable systems is a critical challenge. In the pres…

[Phys. Rev. Lett. 133, 020401] Published Tue Jul 09, 2024

Author(s): Yuexun Huang, Francisco Salces–Carcoba, Rana X. Adhikari, Amir H. Safavi-Naeini, and Liang Jiang

The vacuum beam guide (VBG) presents a completely different solution for quantum channels to overcome the limitations of existing fiber and satellite technologies for long-distance quantum communication. With an array of aligned lenses spaced kilometers apart, the VBG offers ultrahigh transparency o…

[Phys. Rev. Lett. 133, 020801] Published Tue Jul 09, 2024

Author(s): Marric Stephens

Dark matter that interacts with itself could extract significant momentum from a binary supermassive black hole system, causing the black holes to merge.

[Physics 17, s79] Published Tue Jul 09, 2024

Author(s): Abdul Basit, Hamad Ali, Gao Xianlong, Peng-Bo Li, Gehad Sadiek, and Hichem Eleuch

The entropic uncertainty relation imposes a limit on the accuracy of measurement outcomes of two conjugate observables, which can be reduced in the presence of quantum memory. We theoretically study the dynamical behaviors of the quantum-memory-assisted entropic uncertainty relation for a bipartite …

[Phys. Rev. A 110, 012429] Published Tue Jul 09, 2024

Author(s): Peter Brearley and Sylvain Laizet

A quantum algorithm for solving the advection equation by embedding the discrete time-marching operator into Hamiltonian simulations is presented. One-dimensional advection can be simulated directly since the central finite-difference operator for first-order derivatives is anti-Hermitian. Here this…

[Phys. Rev. A 110, 012430] Published Tue Jul 09, 2024

Author(s): Mingjian He and Shouyin Liu

Continuous variable quantum teleportation provides a path to the long-distance transmission of quantum states. Photon-varying non-Gaussian operations have been shown to improve the fidelity of quantum teleportation when integrated into the protocol. However, for a given type of non-Gaussian operatio…

[Phys. Rev. A 110, 012425] Published Tue Jul 09, 2024

Author(s): P. Z. Zhao and Jiangbin Gong

Nonadiabatic holonomic operations are based on nonadiabatic non-Abelian geometric phases, hence possessing the inherent geometric features for robustness against control errors. However, nonadiabatic holonomic operations are still sensitive to the systematic amplitude error induced by imperfect cont…

[Phys. Rev. A 110, 012426] Published Tue Jul 09, 2024

Author(s): Mingzhao Liu (刘铭钊) and Charles T. Black

This paper presents a computational analysis of a superconducting transmon qubit design, in which the superconductor-insulator-superconductor (SIS) Josephson junction is replaced by a coplanar, superconductor-constriction-superconductor (ScS) nanobridge junction. Within the scope of Ginzburg-Landau …

[Phys. Rev. A 110, 012427] Published Tue Jul 09, 2024