QUROPE Quantum Information Processing and Communication in Europe

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): Patryk Lipka-Bartosik, Henrik Wilming, and Nelly H. Y. Ng

A branch of quantum information is concerned with transformations that are possible given certain resources: for example, quantum teleportation moves a quantum state from one place to another, aided by entanglement and classical communication. Certain other tasks are provably impossible. But, as surveyed in this review, a surprising fact is that some tasks become possible if another quantum state is present, even if this state is returned untouched at the end of the task. This “quantum catalysis” enables a large variety of interesting tasks, with applications ranging from cryptography to thermodynamics.

[Rev. Mod. Phys. 96, 025005] Published Thu Jun 27, 2024

Author(s): M. Cristina Volpe

Neutrinos can change flavors due to their nonzero masses and mixings as well as their interactions with matter and other neutrinos. In dense astrophysical environments, such as core-collapse supernovae or neutron star mergers, the problem of neutrino flavor evolution becomes very complex. Connections to other domains such as quantum information theory have been uncovered. Understanding the neutrino flavor evolution in dense environments can shed light on the dynamics of massive star explosions and the origin of heavy elements in the Universe and is important for future observations of supernova neutrinos.

[Rev. Mod. Phys. 96, 025004] Published Mon Jun 24, 2024

Author(s): Mohamadreza Fazel, Kristin S. Grussmayer, Boris Ferdman, Aleksandra Radenovic, Yoav Shechtman, Jörg Enderlein, and Steve Pressé

For centuries, human fascination with the living world motivated the development of tools for visualizing life’s events at the spatiotemporal scales beyond our visual range. While all optical microscopes use light to probe the object of interest, fluorescence microscopes can discern between the object and background at the molecular scale. At this scale, the stochastic properties of light are fundamental to interpreting fluorescence microscopy data. Accordingly quantitative methods that enable such interpretation necessitate stochastic perspective and the use of statistical concepts. The physical-optical principles governing the formation of fluorescent images and modeling tools interpreting these images while accounting for the stochasticity of light and measurements are reviewed.

[Rev. Mod. Phys. 96, 025003] Published Wed Jun 05, 2024

Author(s): Morten Amundsen, Jacob Linder, Jason W. A. Robinson, Igor Žutić, and Niladri Banerjee

In many solids, the spin-orbit interaction is only a small effect. However, in certain materials it leads to new phenomena. This Colloquium reviews the role of spin-orbit interaction in superconducting hybrid structures, where it can lead to exotic states such as spin-triplet pairing, topological superconductivity, and the superconducting diode effect. These are fundamental interest and importance for applications, including spintronics and quantum computing.

[Rev. Mod. Phys. 96, 021003] Published Tue May 28, 2024

Author(s): Qijin Chen, Zhiqiang Wang, Rufus Boyack, Shuolong Yang, and K. Levin

The theory of unconventional superconductors continues to provide profound puzzles. The crossover between the weakly coupled Bardeen-Cooper-Schrieffer (BCS) state and the strong-pairing Bose-Einstein condensate (BEC) provides a useful perspective on how to address these questions. This paper describes a self-consistent framework for thinking about the crossover regime in between these two limits. The review discusses to what extent this BCS-BEC theory applies to a range of classes of superconducting materials including the cuprates, iron pnictides, twisted bilayer graphene, and interfacial superconductivity among others.

[Rev. Mod. Phys. 96, 025002] Published Thu May 23, 2024

Author(s): Randall D. Kamien and Daniel Ucko

[Rev. Mod. Phys. 96, 020001] Published Tue May 21, 2024

Author(s): Jiangfeng Du, Fazhan Shi, Xi Kong, Fedor Jelezko, and Jörg Wrachtrup

Nitrogen-vacancy centers in diamond are sensitive to magnetic fields, and a single center permits detection of electron and nuclear spins and imaging of single molecules in its vicinity. This article reviews the achievements of advanced methods to obtain spectral and spatial resolution and it points to technical problems that remain to be solved for widespread and multidisciplinary adoption of single-molecule magnetic resonance spectroscopy.

[Rev. Mod. Phys. 96, 025001] Published Wed May 08, 2024

Author(s): Tirth Shah, Christian Brendel, Vittorio Peano, and Florian Marquardt

Artificially engineered mechanical systems, sometimes called metamaterials, offer many promising applications on length scales ranging from macroscopic systems to the nanoscale. A topic of particular interest is the existence of topologically protected phononic edge states in such systems that are analogous to the electronic edge states that give rise to the quantum Hall effect. This Colloquium gives an introduction to topologically protected transport in metamaterials and its applications for controlling acoustic transport.

[Rev. Mod. Phys. 96, 021002] Published Thu Apr 18, 2024