CMP Journal 2025-01-13
Statistics
Nature Materials: 2
Nature Physics: 2
Physical Review Letters: 8
Physical Review X: 2
Nature Materials
Resolving and routing magnetic polymorphs in a 2D layered antiferromagnet
Original Paper | Magnetic properties and materials | 2025-01-12 19:00 EST
Zeyuan Sun, Canyu Hong, Yi Chen, Zhiyuan Sheng, Shuang Wu, Zhanshan Wang, Bokai Liang, Wei-Tao Liu, Zhe Yuan, Yizheng Wu, Qixi Mi, Zhongkai Liu, Jian Shen, Shiwei Wu
Polymorphism, commonly denoting diverse molecular or crystal structures, is crucial in the natural sciences. In van der Waals antiferromagnets, a new type of magnetic polymorphism arises, presenting multiple layer-selective magnetic structures with identical total magnetization. However, resolving and manipulating such magnetic polymorphs remain challenging. Here, phase-resolved magnetic second harmonic generation microscopy is used to elucidate magnetic polymorphism in 2D layered antiferromagnet CrSBr, demonstrating deterministic and layer-selective switching of magnetic polymorphs. Using a nonlinear magneto-optical technique, we unambiguously resolve the polymorphic spin-flip transitions in CrSBr bilayers and tetralayers through both the amplitude and phase of light. Remarkably, the deterministic routing of polymorphic spin-flip transitions originates from a ‘layer-sharing' effect, where the transitions are governed by laterally extended layers acting as ‘control bits'. We envision that such controllable magnetic polymorphism could be ubiquitous for van der Waals layered antiferromagnets, enabling new designs and constructions of spintronic and opto-spintronic devices for probabilistic computation and neuromorphic engineering.
Magnetic properties and materials, Magneto-optics, Nonlinear optics, Spintronics, Two-dimensional materials
Morphology remodelling and membrane channel formation in synthetic cells via reconfigurable DNA nanorafts
Original Paper | DNA nanostructures | 2025-01-12 19:00 EST
Sisi Fan, Shuo Wang, Longjiang Ding, Thomas Speck, Hao Yan, Stephan Nussberger, Na Liu
The shape of biological matter is central to cell function at different length scales and determines how cellular components recognize, interact and respond to one another. However, their shapes are often transient and hard to reprogramme. Here we construct a synthetic cell model composed of signal-responsive DNA nanorafts, biogenic pores and giant unilamellar vesicles (GUVs). We demonstrate that reshaping of DNA rafts at the nanoscale can be coupled to reshaping of GUVs at the microscale. The nanorafts collectively undergo reversible transitions between isotropic and short-range local order on the lipid membrane, programmably remodelling the GUV shape. Assisted by the biogenic pores, during GUV shape recovery the locally ordered DNA rafts perforate the membrane, forming sealable synthetic channels for large cargo transport. Our work outlines a versatile platform for interfacing reconfigurable DNA nanostructures with synthetic cells, expanding the potential of DNA nanotechnology in synthetic biology.
DNA nanostructures, Self-assembly
Nature Physics
Direct excitation of Kelvin waves on quantized vortices
Original Paper | Bose-Einstein condensates | 2025-01-12 19:00 EST
Yosuke Minowa, Yuki Yasui, Tomo Nakagawa, Sosuke Inui, Makoto Tsubota, Masaaki Ashida
Helices and spirals, prevalent across various physical systems, play a crucial role in characterizing symmetry, describing dynamics and enabling unique functionalities, all stemming from their inherent simplicity and chiral nature. Helical excitations on quantized vortices, referred to as Kelvin waves, are one example of such a physical system. Kelvin waves play a vital role in energy dissipation within inviscid quantum fluids. However, deliberately exciting Kelvin waves has proven to be challenging. Here we introduce a controlled method for exciting Kelvin waves on a quantized vortex in superfluid helium-4. We used a charged nanoparticle that oscillates when driven by a time-varying electric field to stimulate Kelvin waves on the vortex. Confirmation of the helical nature of Kelvin waves was achieved through three-dimensional image reconstruction, which provided visual evidence of their complex dynamics. Additionally, we determined the dispersion relation and the phase velocity of the Kelvin wave and identified the vorticity direction, thus enhancing our understanding of quantum fluid behaviour. This work elucidates the dynamics of Kelvin waves and initiates an approach for manipulating and observing quantized vortices in three dimensions, thereby opening avenues for exploring quantum fluidic systems.
Bose-Einstein condensates, Fluid dynamics, Quantum fluids and solids
Confinement in a \({\mathbb{Z}}_{2}\) lattice gauge theory on a quantum computer
Original Paper | Nuclear physics | 2025-01-12 19:00 EST
Julius Mildenberger, Wojciech Mruczkiewicz, Jad C. Halimeh, Zhang Jiang, Philipp Hauke
Gauge theories describe the fundamental forces in the standard model of particle physics and play an important role in condensed-matter physics. The constituents of gauge theories, for example, charged matter and electric gauge field, are governed by local gauge constraints, which lead to key phenomena such as the confinement of particles that are not fully understood. In this context, quantum simulators may address questions that are challenging for classical methods. Although engineering gauge constraints is highly demanding, recent advances in quantum computing are beginning to enable digital quantum simulations of gauge theories. Here we simulate confinement dynamics in a \({\mathbb{Z}}_{2}\) lattice gauge theory on a superconducting quantum processor. Tuning a term that couples only to the electric field produces confinement of charges, a manifestation of the tight bond that the gauge constraint generates between both. Moreover, we show how a modification of the gauge constraint from \({\mathbb{Z}}_{2}\) towards U(1) symmetry freezes the system dynamics. Our work illustrates the restriction that the underlying gauge constraint imposes on the dynamics of a lattice gauge theory, showcases how gauge constraints can be modified and protected, and promotes the study of other models governed by multibody interactions.
Nuclear physics, Quantum physics, Quantum simulation
Physical Review Letters
Role of Quantum Coherence in Kinetic Uncertainty Relations
Research article | Fluctuations & noise | 2025-01-13 05:00 EST
Kacper Prech, Patrick P. Potts, and Gabriel T. Landi
The kinetic uncertainty relation (KUR) bounds the signal-to-noise ratio of stochastic currents in terms of the number of transitions per unit time, known as the dynamical activity. This bound was derived in a classical context and can be violated in the quantum regime due to coherent effects. However, the precise connection between KUR violations and quantum coherence has so far remained elusive, despite significant investigation. In this Letter, we solve this problem by deriving a modified bound that exactly pinpoints how, and when, coherence might lead to KUR violations. Our bound is sensitive to the specific kind of unraveling of the quantum master equation. It, therefore, allows one to compare quantum jumps and quantum diffusion, and understand, in each case, how quantum coherence affects fluctuations. We illustrate our result on a double quantum dot, where the electron current is monitored either by electron jump detection or with continuous diffusive charge measurement.
Phys. Rev. Lett. 134, 020401 (2025)
Fluctuations & noise, Open quantum systems, Quantum stochastic processes, Quantum thermodynamics, Quantum dots, Information theory
Inference of the Mass Composition of Cosmic Rays with Energies from \({10}^{18.5}\) to \({10}^{20}\text{ }\text{ }\mathrm{eV}\) Using the Pierre Auger Observatory and Deep Learning
Research article | Cosmic ray & astroparticle detectors | 2025-01-13 05:00 EST
A. Abdul Halim et al. (Pierre Auger Collaboration)
We present measurements of the atmospheric depth of the shower maximum \({X}_{\mathrm{max}\), inferred for the first time on an event-by-event level using the surface detector of the Pierre Auger Observatory. Using deep learning, we were able to extend measurements of the \({X}_{\mathrm{max}\) distributions up to energies of 100 EeV (\({10}^{20}\text{ }\text{ }\mathrm{eV}\)), not yet revealed by current measurements, providing new insights into the mass composition of cosmic rays at extreme energies. Gaining a 10-fold increase in statistics compared to the fluorescence detector data, we find evidence that the rate of change of the average \({X}_{\mathrm{max}\) with the logarithm of energy features three breaks at \(6.5\pm{}0.6(\mathrm{stat})\pm{}1(\mathrm{syst})\text{ }\text{ }\mathrm{EeV}\), \(11\pm{}2(\mathrm{stat})\pm{}1(\mathrm{syst})\text{ }\text{ }\mathrm{EeV}\), and \(31\pm{}5(\mathrm{stat})\pm{}3(\mathrm{syst})\text{ }\text{ }\mathrm{EeV}\), in the vicinity to the three prominent features (ankle, instep, suppression) of the cosmic-ray flux. The energy evolution of the mean and standard deviation of the measured \({X}_{\mathrm{max}\) distributions indicates that the mass composition becomes increasingly heavier and purer, thus being incompatible with a large fraction of light nuclei between 50 and 100 EeV.
Phys. Rev. Lett. 134, 021001 (2025)
Cosmic ray & astroparticle detectors, Cosmic ray acceleration, Cosmic ray composition & spectra, Cosmic ray propagation
Diagnosis for Band Topology under Crystal Symmetries Based on Bulk Measurements
Research article | Photonic crystals | 2025-01-13 05:00 EST
Shiyin Jia, Shiqi Li, Junzheng Hu, Renwen Huang, Jing Li, Biye Xie, Peng Zhan, and Zhenlin Wang
Topological gapped crystalline materials are a class of topological materials characterized by invariants protected by spatial symmetries, allowing for the emergence of robust boundary states. The band topology of gapped materials with crystal symmetries can be theoretically labeled by symmetry-indicator invariants, such as the Fu-Kane parity criterion for inversion-symmetric topological gapped materials. Here, we propose an approach to measuring these invariants and diagnosing topological gapped crystalline materials, which is experimentally validated in two-dimensional photonic crystals with finite size. Notably, this diagnosis approach relies exclusively on the measured field distribution within the bulk region, without necessitating the energy band diagram possessing complete band gaps, even in the absence of in-gap states in real materials. Our study provides an approach for measuring symmetry-indicator invariants and paves the way for experimentally diagnosing various gapped topological phases originating from crystalline symmetries.
Phys. Rev. Lett. 134, 023801 (2025)
Photonic crystals, Microwave techniques, Near-field optical spectroscopy
Hybridized Soliton Lasing in Coupled Semiconductor Lasers
Research article | Coupled oscillators | 2025-01-13 05:00 EST
Theodore P. Letsou, Dmitry Kazakov, Pawan Ratra, Lorenzo L. Columbo, Massimo Brambilla, Franco Prati, Cristina Rimoldi, Sandro Dal Cin, Nikola Opačak, Henry O. Everitt, Marco Piccardo, Benedikt Schwarz, and Federico Capasso
An experiment demonstrates that a chip-scale coupled laser system consisting of a pair of coupled semiconductor ring lasers can exhibit complex optical states impossible to achieve in a single waveguide laser.
Phys. Rev. Lett. 134, 023802 (2025)
Coupled oscillators, Frequency combs & self-phase locking, Integrated optics, Laser dynamics, Solitons
Planar Hall Effect in Quasi-Two-Dimensional Materials
Research article | Berry curvature | 2025-01-13 05:00 EST
Koushik Ghorai, Sunit Das, Harsh Varshney, and Amit Agarwal
Stacked bilayer graphene can demonstrate a 2D planar Hall effect due to factors related to Berry curvature, orbital magnetic moments, and broken symmetries.
Phys. Rev. Lett. 134, 026301 (2025)
Berry curvature, Hall effect, Magnetotransport, Graphene, Layered semiconductors
Minimal Model for Carnot Efficiency at Maximum Power
Research article | Nonequilibrium & irreversible thermodynamics | 2025-01-13 05:00 EST
Shiling Liang (梁师翎), Yu-Han Ma, Daniel Maria Busiello, and Paolo De Los Rios
Carnot efficiency sets a fundamental upper bound on the heat engine efficiency, attainable in the quasistatic limit, albeit at the cost of completely sacrificing power output. Here, we present a minimal heat engine model that can attain Carnot efficiency while achieving maximum power output. We unveil the potential of intrinsic divergent physical quantities within the working substance, such as degeneracy, as promising thermodynamic resources to break through the universal power-efficiency trade-off imposed by nonequilibrium thermodynamics for conventional heat engines. Our findings provide novel insights into the collective advantage in harnessing energy of many-body interacting systems.
Phys. Rev. Lett. 134, 027101 (2025)
Nonequilibrium & irreversible thermodynamics, Nonequilibrium statistical mechanics, Stochastic thermodynamics, Efficiency at maximum power, Heat engines, Master equation
Asymmetric Simple Exclusion Process on the Percolation Cluster: Waiting Time Distribution in Side Branches
Research article | Directed percolation | 2025-01-13 05:00 EST
Chandrashekar Iyer, Mustansir Barma, Hunnervir Singh, and Deepak Dhar
As the simplest model of transport of interacting particles in a disordered medium, we consider the asymmetric simple exclusion process (ASEP) in which particles with hard-core interactions perform biased random walks, on the supercritical percolation cluster. In this process, the long time trajectory of a marked particle consists of steps on the backbone, punctuated by time spent in side branches. We study the probability distribution in the steady state of the waiting time \({T}_{w}\) of a randomly chosen particle, in a side branch since its last step along the backbone. Exact numerical evaluation of this on a single side branch of length \(L=1\) to 9 shows that for large fields, the probability distribution of \(\mathrm{log}{T}_{w}\) has multiple well separated peaks. We extend this result to a regular comb, and to the ASEP on the percolation cluster. We show that in the steady state, the fractional number of particles that have been in the same side branch for a time interval greater than \({T}_{w}\) varies as \(\mathrm{exp}(- c\sqrt{\mathrm{log}{T}_{w})\) for large \({T}_{w}\), where \(c\) depends only on the bias field. However, these long timescales are not reflected in the eigenvalue spectrum of the Markov evolution matrix. The system shows dynamical heterogeneity, with particles segregating into pockets of high and low mobilities.
Phys. Rev. Lett. 134, 027102 (2025)
Directed percolation, Nonequilibrium statistical mechanics, Random walks, Disordered systems, Lattice models in statistical physics, Monte Carlo methods
Smooth Exact Gradient Descent Learning in Spiking Neural Networks
Research article | Learning | 2025-01-13 05:00 EST
Christian Klos and Raoul-Martin Memmesheimer
By incorporating electrical pulses with shapes similar to those of the spikes from biological neurons, researchers improved the ability to train energy-efficient types of neural networks.
Phys. Rev. Lett. 134, 027301 (2025)
Learning, Neuronal dynamics, Neuroscience, neural computation & artificial intelligence, Spiking neurons, Artificial neural networks, Dynamical systems, Deep learning, Integrate-and-fire model, Spiking neuron models
Physical Review X
Efficient Prediction of Superlattice and Anomalous Miniband Topology from Quantum Geometry
Research article | Crystal symmetry | 2025-01-13 05:00 EST
Valentin Crépel and Jennifer Cano
Predicting which superlattice materials are best for observing specific topological states is often computationally prohibitive. A new method for doing so bypasses that hurdle.
Phys. Rev. X 15, 011004 (2025)
Crystal symmetry, Quantum anomalous Hall effect, Twisted heterostructures, Wigner crystal, Topology
Recurrences Reveal Shared Causal Drivers of Complex Time Series
Research article | Chaos | 2025-01-13 05:00 EST
William Gilpin
Many complex systems are driven by unobserved causal forces. A new physics-based algorithm can reconstruct such hidden causes from downstream signals.
Phys. Rev. X 15, 011005 (2025)
Chaos, Network diffusion, Chaos & nonlinear dynamics, Information theory, Time series analysis