Nonlocal Temporal Interferometry for Highly Resilient Free-Space Quantum Communication Lukas Bulla, Matej Pivoluska, Kristian Hjorth, Oskar Kohout, Jan Lang, Sebastian Ecker, Sebastian P. Neumann, Julius Bittermann, Robert Kindler, Marcus Huber, Martin Bohmann, and Rupert Ursin Phys. Rev. X 13, 021001 (2023) – Published 3 April 2023 High-dimensional entanglement among photons allows for a roughly 10-km free-space quantum communication link in an urban environment that is robust to noise. Show Abstract Optics Quantum Physics Quantum Information PDFHTML Quantitatively Visualizing Bipartite Datasets Tal Einav, Yuehaw Khoo, and Amit Singer Phys. Rev. X 13, 021002 (2023) – Published 4 April 2023 A new tool transforms pairwise interactions within a dataset into a cohesive global picture that predicts how the system can behave. Show Abstract Biological Physics Computational Physics PDFHTML Disentangling Representations in Restricted Boltzmann Machines without Adversaries Jorge Fernandez-de-Cossio-Diaz, Simona Cocco, and Rémi Monasson Phys. Rev. X 13, 021003 (2023) – Published 5 April 2023 A new way for machine learning to disentangle representations of complex data relies on a single, simple model rather than adversarial training of two competing neural networks. Show Abstract Computational Physics Statistical Physics PDFHTML Protecting the Quantum Interference of Cat States by Phase-Space Compression Xiaozhou Pan, Jonathan Schwinger, Ni-Ni Huang, Pengtao Song, Weipin Chua, Fumiya Hanamura, Atharv Joshi, Fernando Valadares, Radim Filip, and Yvonne Y. Gao Phys. Rev. X 13, 021004 (2023) – Published 7 April 2023 Compressing the spectral content of quantum interference features in Schrödinger cat states to lower frequencies protects them against photon loss and preserves the most valuable characteristics that enable many quantum technologies. Show Abstract Quantum Physics Quantum Information PDFHTML Demon in the Machine: Learning to Extract Work and Absorb Entropy from Fluctuating Nanosystems Stephen Whitelam Phys. Rev. X 13, 021005 (2023) – Published 10 April 2023 A deep neural network learns feedback-control protocols that convert information obtained from measuring a fluctuating nanosystem into heat or work. Show Abstract Complex Systems Computational Physics Statistical Physics PDFHTML Weight versus Node Perturbation Learning in Temporally Extended Tasks: Weight Perturbation Often Performs Similarly or Better Paul Züge, Christian Klos, and Raoul-Martin Memmesheimer Phys. Rev. X 13, 021006 (2023) – Published 11 April 2023 In neural networks, a reward-based rule that relies on perturbing network weights can perform as well as or better than the more commonly studied node perturbation approach. Show Abstract Biological Physics Computational Physics Statistical Physics PDFHTML Entanglement Phase Transition Induced by the Non-Hermitian Skin Effect Kohei Kawabata, Tokiro Numasawa, and Shinsei Ryu Phys. Rev. X 13, 021007 (2023) – Published 12 April 2023 In open quantum systems, a macroscopic flow of particles and concomitant anomalous localization play an important role in the entanglement dynamics. Show Abstract Condensed Matter Physics Quantum Physics Statistical Physics PDFHTML Superconducting Fluctuations Observed Far above T c in the Isotropic Superconductor K 3 C 60 Gregor Jotzu, Guido Meier, Alice Cantaluppi, Andrea Cavalleri, Daniele Pontiroli, Mauro Riccò, Arzhang Ardavan, and Moon-Sun Nam Phys. Rev. X 13, 021008 (2023) – Published 17 April 2023 Precursors of superconductivity well above the critical temperature in K 3 C 60 imply the presence of Cooper pairs at high temperature, which may help explain why light can raise the critical temperature of this material. Show Abstract Condensed Matter Physics Strongly Correlated Materials Superconductivity PDFHTML Uncovering Conformal Symmetry in the 3D Ising Transition: State-Operator Correspondence from a Quantum Fuzzy Sphere Regularization Wei Zhu, Chao Han, Emilie Huffman, Johannes S. Hofmann, and Yin-Chen He Phys. Rev. X 13, 021009 (2023) – Published 18 April 2023 A new theoretical scheme of studying the 3D Ising transition—a celebrated phase transition in a model of ferromagnetism—provides insights into the conformal symmetry long conjectured to emerge. Show Abstract Condensed Matter Physics Statistical Physics String Theory PDFHTML Single-Molecule Structure and Topology of Kinetoplast DNA Networks Pinyao He, Allard J. Katan, Luca Tubiana, Cees Dekker, and Davide Michieletto Phys. Rev. X 13, 021010 (2023) – Published 19 April 2023 This high-resolution imaging study investigates a unique interlinked DNA found in certain single-cell parasites and reveals the genome’s unusual structure and topology at single-molecule resolution. Show Abstract Biological Physics Soft Matter PDFHTML Limits and Performances of Algorithms Based on Simulated Annealing in Solving Sparse Hard Inference Problems Maria Chiara Angelini and Federico Ricci-Tersenghi Phys. Rev. X 13, 021011 (2023) – Published 20 April 2023 A new theory, supported by large-scale numerical simulations, explores the conditions under which two Monte Carlo–based optimization algorithms can extract a signal from noisy data. Show Abstract Computational Physics Interdisciplinary Physics Statistical Physics PDFHTML Symmetries as the Guiding Principle for Flattening Bands of Dirac Fermions Yarden Sheffer, Raquel Queiroz, and Ady Stern Phys. Rev. X 13, 021012 (2023) – Published 24 April 2023 A new criterion for determining what materials can be fine-tuned to have very slowly moving electrons could lead to new platforms for studying novel phenomena arising from electron correlation. Show Abstract Condensed Matter Physics PDFHTML Emergent s -Wave Interactions between Identical Fermions in Quasi-One-Dimensional Geometries Kenneth G. Jackson, Colin J. Dale, Jeff Maki, Kevin G. S. Xie, Ben A. Olsen, Denise J. M. Ahmed-Braun, Shizhong Zhang, and Joseph H. Thywissen Phys. Rev. X 13, 021013 (2023) – Published 25 April 2023 The wave function of fermions always acquires a minus sign when particles trade places. But an experiment shows that fermions confined to a quasi-one-dimensional space seem to circumvent this exchange symmetry. Show Abstract Atomic and Molecular Physics Condensed Matter Physics PDFHTML Featured in Physics Kinetic Turbulence in Collisionless High- β Plasmas Lev Arzamasskiy, Matthew W. Kunz, Jonathan Squire, Eliot Quataert, and Alexander A. Schekochihin Phys. Rev. X 13, 021014 (2023) – Published 26 April 2023 Physics logo Viewpoint: Turbulence in Collisionless Cosmic Plasmas New computer simulations show that wave-particle interactions endow thin plasmas with an effective viscosity that regulates their turbulent motions and heating. Show Abstract Astrophysics Plasma Physics PDFHTML Multiscale Space-Time Ansatz for Correlation Functions of Quantum Systems Based on Quantics Tensor Trains Hiroshi Shinaoka, Markus Wallerberger, Yuta Murakami, Kosuke Nogaki, Rihito Sakurai, Philipp Werner, and Anna Kauch Phys. Rev. X 13, 021015 (2023) – Published 27 April 2023 A new way of encoding multipoint correlation functions—key to representing complex correlations among particles—greatly reduces their computation time and storage requirements. Show Abstract Computational Physics Condensed Matter Physics PDFHTML Observation of Spin-Wave Moiré Edge and Cavity Modes in Twisted Magnetic Lattices Hanchen Wang, Marco Madami, Jilei Chen, Hao Jia, Yu Zhang, Rundong Yuan, Yizhan Wang, Wenqing He, Lutong Sheng, Yuelin Zhang, Jinlong Wang, Song Liu, Ka Shen, Guoqiang Yu, Xiufeng Han, Dapeng Yu, Jean-Philippe Ansermet, Gianluca Gubbiotti, and Haiming Yu Phys. Rev. X 13, 021016 (2023) – Published 28 April 2023 The first experimental demonstration of magnons, or spin waves, in a nanostructured moiré lattice sets the stage for exploring the potential role of such systems in novel magnonic devices for information processing. Show Abstract Condensed Matter Physics Magnetism PDFHTML Consistent Quantization of Nearly Singular Superconducting Circuits Martin Rymarz and David P. DiVincenzo Phys. Rev. X 13, 021017 (2023) – Published 1 May 2023 An analysis of a common approach to describing singular superconducting circuits quantum mechanically shows that it can lead to wrong predictions of the system’s dynamics. Show Abstract Electronics Quantum Physics Quantum Information PDFHTML Featured in Physics Timescales of Chaos in the Inner Solar System: Lyapunov Spectrum and Quasi-integrals of Motion Federico Mogavero, Nam H. Hoang, and Jacques Laskar Phys. Rev. X 13, 021018 (2023) – Published 3 May 2023 Physics logo Viewpoint: Tackling the Puzzle of Our Solar System’s Stability A new theory explains why our planets avoid collisions for far longer times than standard theories of planetary stability predict. Show Abstract Gravitation Nonlinear Dynamics Statistical Physics PDFHTML Gravitational-Wave Detector for Postmerger Neutron Stars: Beyond the Quantum Loss Limit of the Fabry-Perot-Michelson Interferometer Teng Zhang, Huan Yang, Denis Martynov, Patricia Schmidt, and Haixing Miao Phys. Rev. X 13, 021019 (2023) – Published 4 May 2023 A simple modification to gravitational wave detector designs could allow future observatories to study the postmerger physics of a binary neutron star merger, to which current facilities are not sensitive. Show Abstract Astrophysics Gravitation Optics PDFHTML Frequency-Resolved Atlas of the Sky in Continuous Gravitational Waves Vladimir Dergachev and Maria Alessandra Papa Phys. Rev. X 13, 021020 (2023) – Published 5 May 2023 The first ever “atlas” of continuous gravitational-wave amplitudes at every point on the sky provides a rich dataset in which to conduct searches for nonaxisymmetric neutron stars. Show Abstract Astrophysics Gravitation PDFHTML Quantum Simulations of Interacting Systems with Broken Time-Reversal Symmetry Yotam Shapira, Tom Manovitz, Nitzan Akerman, Ady Stern, and Roee Ozeri Phys. Rev. X 13, 021021 (2023) – Published 9 May 2023 A trapped-ion quantum computer simulates the behavior of many-body quantum spin systems with interesting geometries and the effects of magnetic fields and interactions on them. Show Abstract Atomic and Molecular Physics Quantum Physics PDFHTML Featured in Physics Molecular Tug of War Reveals Adaptive Potential of an Immune Cell Repertoire Hongda Jiang and Shenshen Wang Phys. Rev. X 13, 021022 (2023) – Published 10 May 2023 Physics logo Viewpoint: The Mechanical Struggle behind Adaptive Immunity A study of the mechanical forces in certain immune cells may give new insights into how organisms deal with ever-evolving pathogens. Show Abstract Biological Physics Interdisciplinary Physics Statistical Physics PDFHTML Optical Coherent Feedback Control of a Mechanical Oscillator Maryse Ernzer, Manel Bosch Aguilera, Matteo Brunelli, Gian-Luca Schmid, Thomas M. Karg, Christoph Bruder, Patrick P. Potts, and Philipp Treutlein Phys. Rev. X 13, 021023 (2023) – Published 15 May 2023 The first demonstration of optical coherent feedback in an optomechanical system controls the motion of a mechanical oscillator and cools it by more than 4 orders of magnitude, a prerequisite for quantum applications. Show Abstract Optics Quantum Physics PDFHTML Non-Abelian Frame Charge Flow in Photonic Media Dongyang Wang, Ying Wu, Z. Q. Zhang, and C. T. Chan Phys. Rev. X 13, 021024 (2023) – Published 16 May 2023 Non-Abelian frame charges—mathematical entities used to describe certain topological properties—can also help understand band degeneracies in ordinary optical media. Show Abstract Metamaterials Optics Topological Insulators PDFHTML Periodic Atomic Displacements and Visualization of the Electron-Lattice Interaction in the Cuprate Zengyi Du, Hui Li, Genda Gu, Abhay N. Pasupathy, John M. Tranquada, and Kazuhiro Fujita Phys. Rev. X 13, 021025 (2023) – Published 17 May 2023 A novel technique reveals a high-fidelity local distortion of the atomic lattice in the charge-density-wave state of a cuprate, providing the first direct evidence of electron-lattice coupling in real space. Show Abstract Condensed Matter Physics Strongly Correlated Materials Superconductivity PDFHTML Measurements Conspire Nonlocally to Restructure Critical Quantum States Samuel J. Garratt, Zack Weinstein, and Ehud Altman Phys. Rev. X 13, 021026 (2023) – Published 18 May 2023 When quantum critical states are measured in many locations, new collective phenomena can emerge. There are transitions between two regimes: one where the effects of measurements on correlations are negligible, and one where they are dramatic. Show Abstract Condensed Matter Physics Quantum Physics Statistical Physics PDFHTML Nonlinear Networks for Arbitrary Optical Synthesis Jennifer A. Black, Zachary L. Newman, Su-Peng Yu, David R. Carlson, and Scott B. Papp Phys. Rev. X 13, 021027 (2023) – Published 19 May 2023 A demonstration of an optical synthesizer—a laser light source whose wavelength can be programmed—showcases a tool that can provide arbitrary wavelength access to applications such as signal processing and quantum sensing. Show Abstract Photonics PDFHTML Performing SU ( d ) Operations and Rudimentary Algorithms in a Superconducting Transmon Qudit for d = 3 and d = 4 Pei Liu, Ruixia Wang, Jing-Ning Zhang, Yingshan Zhang, Xiaoxia Cai, Huikai Xu, Zhiyuan Li, Jiaxiu Han, Xuegang Li, Guangming Xue, Weiyang Liu, Li You, Yirong Jin, and Haifeng Yu Phys. Rev. X 13, 021028 (2023) – Published 23 May 2023 A multilevel qubit, or “qudit,” in a superconducting transmon shows high fidelity with several rudimentary algorithms, demonstrating the potential of a quantum computing architecture based on up to four levels rather than just two. Show Abstract Quantum Physics Quantum Information PDFHTML Perturbations of Spinning Black Holes beyond General Relativity: Modified Teukolsky Equation Dongjun Li, Pratik Wagle, Yanbei Chen, and Nicolás Yunes Phys. Rev. X 13, 021029 (2023) – Published 25 May 2023 A mathematical formalism for studying quasinormal gravitational-wave modes from coalescing black holes provides a tool for testing modifications to general relativity. Show Abstract Astrophysics Gravitation PDFHTML Featured in Physics Real-Time Early Detection of Crack Propagation Precursors in Delayed Fracture of Soft Elastomers Jianzhu Ju, Gabriel E. Sanoja, Med Yassine Nagazi, Luca Cipelletti, Zezhou Liu, Chung Yuen Hui, Matteo Ciccotti, Tetsuharu Narita, and Costantino Creton Phys. Rev. X 13, 021030 (2023) – Published 26 May 2023 Physics logo Focus: Predicting When a Material Will Crack A combination of two techniques provides warning signs that the stress on a material will lead to failure. Show Abstract Mechanics Optics Soft Matter PDFHTML Featured in Physics Einstein-Podolsky-Rosen Experiment with Two Bose-Einstein Condensates Paolo Colciaghi, Yifan Li, Philipp Treutlein, and Tilman Zibold Phys. Rev. X 13, 021031 (2023) – Published 30 May 2023 Physics logo Viewpoint: Realizing the Einstein-Podolsky-Rosen Paradox for Atomic Clouds A new demonstration involving hundreds of entangled atoms tests Schrödinger’s interpretation of Einstein, Rosen, and Podolsky’s classic thought experiment. Show Abstract Quantum Physics PDFHTML Why Are There Six Degrees of Separation in a Social Network? I. Samoylenko, D. Aleja, E. Primo, K. Alfaro-Bittner, E. Vasilyeva, K. Kovalenko, D. Musatov, A. M. Raigorodskii, R. Criado, M. Romance, D. Papo, M. Perc, B. Barzel, and S. Boccaletti Phys. Rev. X 13, 021032 (2023) – Published 31 May 2023 The “six degrees of separation” are the property of the equilibrium state of any network where individuals weigh their aspiration to improve their centrality against the costs incurred in forming or maintaining connections. Show Abstract Complex Systems PDFHTML Electronic and Structural Fingerprints of Charge-Density-Wave Excitations in Extreme Ultraviolet Transient Absorption Spectroscopy Tobias Heinrich, Hung-Tzu Chang, Sergey Zayko, Kai Rossnagel, Murat Sivis, and Claus Ropers Phys. Rev. X 13, 021033 (2023) – Published 7 June 2023 Measurements of titanium diselenide differentiate between the material’s optical phonons and charge-density-wave excitations, showing the use of tabletop extreme ultraviolet spectroscopy to probe charge-density-wave dynamics. Show Abstract Condensed Matter Physics Optics Strongly Correlated Materials PDFHTML A Nonlinear Fluctuation-Dissipation Test for Markovian Systems Kirsten Engbring, Dima Boriskovsky, Yael Roichman, and Benjamin Lindner Phys. Rev. X 13, 021034 (2023) – Published 12 June 2023 A new test for determining whether time-series data is Markovian overcomes limitations of existing techniques and lays a foundation for the simple classification of diverse nonequilibrium systems. Show Abstract Interdisciplinary Physics Soft Matter Statistical Physics PDFHTML Featured in Physics Probing Accretion Physics with Gravitational Waves Lorenzo Speri, Andrea Antonelli, Laura Sberna, Stanislav Babak, Enrico Barausse, Jonathan R. Gair, and Michael L. Katz Phys. Rev. X 13, 021035 (2023) – Published 15 June 2023 Physics logo Synopsis: Accretion Explored through Gravitational Waves Future space-based gravitational-wave detectors could probe the physics of accretion disks surrounding massive black holes. Show Abstract Astrophysics Gravitation PDFHTML Precision Measurement of the Excited State Landé g-factor and Diamagnetic Shift of the Cesium D 2 Line Hans Stærkind, Kasper Jensen, Jörg H. Müller, Vincent O. Boer, Esben T. Petersen, and Eugene S. Polzik Phys. Rev. X 13, 021036 (2023) – Published 20 June 2023 High-magnetic-field optical magnetometry requires precise information on how atomic resonances respond to those fields. New measurements of the relevant coefficients in cesium provide parts-per-million accuracy. Show Abstract Atomic and Molecular Physics Optics PDFHTML Ferromagnetism in an Extended Coherently Coupled Atomic Superfluid R. Cominotti, A. Berti, C. Dulin, C. Rogora, G. Lamporesi, I. Carusotto, A. Recati, A. Zenesini, and G. Ferrari Phys. Rev. X 13, 021037 (2023) – Published 21 June 2023 Experiments with coherently coupled superfluid mixtures investigate the magnetic properties across the paramagnetic-to-ferromagnetic phase transition in the absence of dissipative effects. Show Abstract Atomic and Molecular Physics Magnetism Superfluidity PDFHTML Emergence of Geometric Turing Patterns in Complex Networks Jasper van der Kolk, Guillermo García-Pérez, Nikos E. Kouvaris, M. Ángeles Serrano, and Marián Boguñá Phys. Rev. X 13, 021038 (2023) – Published 22 June 2023 By describing network topology using an underlying geometric space, spatial Turing patterns can be found in the geometric embeddings of real networks. Show Abstract Complex Systems Interdisciplinary Physics Nonlinear Dynamics PDFHTML Featured in Physics Resonance Fluorescence of a Chiral Artificial Atom Chaitali Joshi, Frank Yang, and Mohammad Mirhosseini Phys. Rev. X 13, 021039 (2023) – Published 26 June 2023 Physics logo Viewpoint: Artificial Atoms Go Chiral A device’s selective interaction with left- and right-propagating modes could pave the way for directional information flow in quantum computing based on superconducting circuits. Show Abstract Nonlinear Dynamics Optics Quantum Physics PDFHTML Geometry of Nonequilibrium Reaction Networks Sara Dal Cengio, Vivien Lecomte, and Matteo Polettini Phys. Rev. X 13, 021040 (2023) – Published 27 June 2023 A new framework for analyzing forces and currents in nonequilibrium systems generalizes existing graph-theoretical tools to now encompass interacting reaction networks and time-dependent properties. Show Abstract Chemical Physics Complex Systems Statistical Physics PDFHTML Circuit Theory for Chemical Reaction Networks Francesco Avanzini, Nahuel Freitas, and Massimiliano Esposito Phys. Rev. X 13, 021041 (2023) – Published 27 June 2023 Just as circuit theory breaks complex electrical circuits into simpler components, a new framework does the same for chemical reaction networks, providing tools to simplify the analysis of molecule and energy flow. Show Abstract Chemical Physics Statistical Physics PDFHTML Observation of Brane Parity Order in Programmable Optical Lattices David Wei, Daniel Adler, Kritsana Srakaew, Suchita Agrawal, Pascal Weckesser, Immanuel Bloch, and Johannes Zeiher Phys. Rev. X 13, 021042 (2023) – Published 29 June 2023 A new technique for emulating 2D lattice models with programmable geometries provides support for nonlocal order in 2D Hubbard models of interacting bosons. Show Abstract Atomic and Molecular Physics PDFHTML Erratum: Hierarchy of Linear Light Cones with Long-Range Interactions [Phys. Rev. X 10, 031009 (2020)] Minh C. Tran, Chi-Fang Chen, Adam Ehrenberg, Andrew Y. Guo, Abhinav Deshpande, Yifan Hong, Zhe-Xuan Gong, Alexey V. 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