CMP Journal 2025-01-07

Statistics

Physical Review Letters: 10

Physical Review Letters

Correlations Enable Lossless Ergotropy Transport

Research article | Batteries | 2025-01-07 05:00 EST

Rick P. A. Simon, Janet Anders, and Karen V. Hovhannisyan

''A battery powers a device'' can be read as ''work stored in the battery is being transported to the device.'' In quantum batteries, the total amount of stored work can be measured by ergotropy, which is the maximal work extractable by unitary operations. Transporting ergotropy is fundamentally different from transporting energy, and here we find that ergotropy can be gained even when the transmission channel is strictly energy conserving. We show that, generically, ergotropy transport is lossy whenever the two systems start uncorrelated. In contrast, for a large class of correlated initial states, transport can be gainful. Furthermore, a single correlated state can be used multiple times, allowing to transport without losses an order of magnitude more work than the battery capacity. Correlations are thus a useful resource for ergotropy transport, and we quantify how this resource is consumed during gainful transport.

Phys. Rev. Lett. 134, 010408 (2025)

Batteries, Energy transport, Quantum correlations in quantum information, Quantum information theory, Quantum statistical mechanics, Quantum thermodynamics, Quantum transport

Defect Production across Higher-Order Phase Transitions beyond Kibble-Zurek Scaling

Research article | Critical phenomena | 2025-01-07 05:00 EST

Menghua Deng, Zhoujian Sun, and Fuxiang Li

The Kibble-Zurek mechanism predicts a universal scaling behavior of the defect production when a system is slowly quenched across a critical phase transition point. Here, we discover that the universal scaling behavior across a higher-order topological phase transition does not conform to the traditional Kibble-Zurek mechanism. To explain the anomalous scaling exponent, we develop a solvable Landau-Zener model that takes into account the role of topological edge band that dominates the phase transition. For a two-dimensional boundary-obstructed higher-order topological system, the Kibble-Zurek scaling must be modified to adopt the effective dimension of topological edge band instead of the real physical dimension. We also find that across the boundary-obstructed higher-order topological phase transition, boundary conditions can drastically modify the scaling behaviors. For comparison, we investigate the slow quench dynamics across the bulk-obstructed phase transitions and a single multicritical point, which obeys the Kibble-Zurek mechanism with physical dimension.

Phys. Rev. Lett. 134, 010409 (2025)

Critical phenomena, Landau-Zener effect, Nonequilibrium statistical mechanics, Quantum phase transitions, Quantum quench, Topological insulators, Topological phase transition, Nonequilibrium systems

Fundamental Limits of Metrology at Thermal Equilibrium

Research article | Critical phenomena | 2025-01-07 05:00 EST

Paolo Abiuso, Pavel Sekatski, John Calsamiglia, and Martí Perarnau-Llobet

We consider the estimation of an unknown parameter $$ through a quantum probe at thermal equilibrium. The probe is assumed to be in a Gibbs state according to its Hamiltonian \({H}_{\theta }\), which is divided in a parameter-encoding term \({H}_{\theta }^{\mathrm{P}}\) and an additional, parameter-independent control \({H}^{\mathrm{C}}\). Given a fixed encoding, we find the maximal quantum Fisher information attainable via arbitrary \({H}^{\mathrm{C}}\), which provides a fundamental bound on the measurement precision. We elucidate the role of quantum coherence between encoding and control in different temperature regimes, which include ground state metrology as a limiting case. In the case of locally encoded parameters, the optimal sensitivity presents an \({N}^{2}\) scaling in terms of the number of particles of the probe, which can be reached, at finite temperature, with local measurements and no entanglement. We apply our results to paradigmatic spin chain models, showing that these fundamental limits can be approached using local two-body interactions. Our results set the fundamental limits and optimal control for metrology with thermal and ground state probes, including probes at the verge of criticality.

Phys. Rev. Lett. 134, 010801 (2025)

Critical phenomena, Information thermodynamics, Quantum Fisher information, Quantum control, Quantum criticality, Quantum metrology, Quantum parameter estimation

Star Cluster Population of High Mass Black Hole Mergers in Gravitational Wave Data

Research article | Formation & evolution of stars & galaxies | 2025-01-07 05:00 EST

Fabio Antonini, Isobel M. Romero-Shaw, and Thomas Callister

Stellar evolution theories predict a gap in the black hole birth mass spectrum as the result of pair instability processes in the cores of massive stars. This gap, however, is not seen in the binary black hole masses inferred from gravitational wave data. One explanation is that black holes form dynamically in dense star clusters where smaller black holes merge to form more massive black holes, populating the mass gap. We show that this model predicts a distribution of the effective and precessing spin parameters, \({\chi }_{\mathrm{eff}}\) and \({\chi }_{\mathrm{p}}\), within the mass gap that is insensitive to assumptions about black hole natal spins and other astrophysical parameters. We analyze the distribution of \({\chi }_{\mathrm{eff}}\) as a function of primary mass for the black hole binaries in the third gravitational wave transient catalog. We infer the presence of a high mass and isotropically spinning population of black holes that is consistent with hierarchical formation in dense star clusters and a pair-instability mass gap with a lower edge at \({44}_{- 4}^{+6}{M}_{\bigodot }\). We compute a Bayes factor \(\mathcal{B}>{10}^{4}\) relative to models that do not allow for a high mass population with a distinct \({\chi }_{\mathrm{eff}}\) distribution. Upcoming data will enable us to tightly constrain the hierarchical formation hypothesis and refine our understanding of binary black hole formation.

Phys. Rev. Lett. 134, 011401 (2025)

Formation & evolution of stars & galaxies, Gravitational waves

Study of \({D}_{s}^{+}\rightarrow {f}_{0}(980){\rho }^{+}\) and \(\phi {\pi }^{+}\) Decays through \({D}_{s}^{+}\rightarrow {\pi }^{+}{\pi }^{+}{\pi }^{- }{\pi }^{0}\)

Research article | Electroweak interaction | 2025-01-07 05:00 EST

M. Ablikim et al. (BESIII Collaboration)

We perform the first amplitude analysis of \({D}_{s}^{+}\rightarrow {\pi }^{+}{\pi }^{+}{\pi }^{- }{\pi }^{0}\) decays based on data samples of electron-positron collisions recorded with the BESIII detector at center-of-mass energies between 4.128 and 4.226 GeV, corresponding to an integrated luminosity of \(7.33\text{ }\text{ }{\mathrm{fb}}^{- 1}\). We report the observation of \({D}_{s}^{+}\rightarrow {f}_{0}(980)\rho (770{)}^{+}\) with a statistical significance greater than $10$ and determine the branching fractions \(\mathcal{B}({D}_{s}^{+}\rightarrow {\pi }^{+}{\pi }^{+}{\pi }^{- }{\pi }^{0}{|}_{\mathrm{non}- \eta })=(2.04\pm{}0.0{8}_{\mathrm{stat}}\pm{}0.0{5}_{\mathrm{syst}})%\) and \(\mathcal{B}({D}_{s}^{+}\rightarrow \eta {\pi }^{+})=(1.56\pm{}0.0{9}_{\mathrm{stat}}\pm{}\phantom{\rule{0ex}{0ex}}0.0{4}_{\mathrm{syst}})%\). Moreover, we measure the relative branching fraction between \(\phi \rightarrow {\pi }^{+}{\pi }^{- }{\pi }^{0}\) and \(\phi \rightarrow {K}^{+}{K}^{- }\) to be \([\mathcal{B}(\phi (1020)\rightarrow {\pi }^{+}{\pi }^{- }{\pi }^{0})/\mathcal{B}(\phi (1020)\rightarrow {K}^{+}{K}^{- })]=0.230\pm{}0.01{4}_{\mathrm{stat}}\pm{}0.01{0}_{\mathrm{syst}}\)., which deviates from the world average value by more than $4$.

Phys. Rev. Lett. 134, 011904 (2025)

Electroweak interaction, W & Z bosons, Charmed mesons, Exotic mesons, Light mesons

Topological Spin States in 3D Coupled Electromagnetic Fields

Research article | Nanophotonics | 2025-01-07 05:00 EST

Liang Fang, Yuanjiang Xiang, Qinjun Chen, and Shuangchun Wen

Topological defects are nonsmooth field configurations with singularities that widely exist in physics and multidisciplinary areas. Here, we introduce near-field polarization evolution and the resulting topological spin states in a system of silicon-based coupled waveguides. The topological spin structures originate from 3D evanescent field coupling that transforms the trivial transverse spin into the topological spin states in a 2D plane. Moreover, we show that the periodic coupling of higher-order electromagnetic modes can produce intriguing spin defect (singularity) arrays, including those with alternately topological charges of \(\pm{}1\). These findings may further expand the family of electromagnetic topological structures, and open new avenues to engineer photon emission and light-matter interactions on integrated photonic platforms.

Phys. Rev. Lett. 134, 013801 (2025)

Nanophotonics, Near-field optics, Optical vortices, Spin texture, Topological defects, Topological effects in photonic systems, Waveguides, Spin

Dual-Color Coherent Perfect Absorber

Research article | Nonlinear optics | 2025-01-07 05:00 EST

Boyi Xue, Jintian Lin, Jiankun Hou, Yicheng Zhu, Ruixin Ma, Xianfeng Chen, Ya Cheng, Li Ge, and Wenjie Wan

Perfect absorption of light critically affects light-matter interaction for various applications. Coherent perfect absorbers (CPAs) gain the unique capability of controlling light with light in a linear fashion. Multicolor CPAs [S. Longhi, Time-reversed optical parametric oscillation, Phys. Rev. Lett. 107, 033901 (2011)] are highly desirable for broadband and nonlinear light-to-light coherent control but the experimental demonstration has still remained elusive. Here, for the first time, we experimentally observe a dual-color version of a CPA (DC-CPA) through a second harmonic generation in a single whispering-gallery-mode microcavity. The DC-CPA enables simultaneous perfect absorption of both the incoming fundamental wave and its second harmonic. Similar to its linear counterpart, coherent control in the DC-CPA can also be realized by tuning the relative phase and intensity between the two-colored waves through nonlinear interference instead of the linear one. This scheme breaks the linear boundary of the traditional CPA into a multifrequency domain and paves the way toward all-optical signal processing and quantum information.

Phys. Rev. Lett. 134, 013802 (2025)

Nonlinear optics, Microcavity & microdisk lasers, Non-Hermitian systems, Coherent control, Optical second-harmonic generation

Sedimentation Dynamics of Bodies with Two Planes of Symmetry

Research article | Fluid-particle interactions | 2025-01-07 05:00 EST

Harshit Joshi and Rama Govindarajan

We show that bodies with two planes of symmetry can display a range of behaviors even without inertia. Any such body supports a conserved quantity in its dynamics, and is either a settler, a drifter or a flutterer, depending only on its shape. At large time, settlers and drifters, respectively, fall vertically and obliquely, while flutterers rotate forever while executing intricate patterns. The dynamics of flutterers decouples into a periodic and a Floquet part with different timescales, giving periodicity or quasiperiodicity. We design a set of bodies and use the boundary integral method to show that settlers, drifters, and flutterers, all lie in this set.

Phys. Rev. Lett. 134, 014002 (2025)

Fluid-particle interactions, Low Reynolds number flows, Nonlinear dynamics in fluids, Particle-laden flows, Stokesian dynamics, Boundary element method, Stokes equations

Blending Optimal Control and Biologically Plausible Learning for Noise-Robust Physical Neural Networks

Research article | Analog computation | 2025-01-07 05:00 EST

Satoshi Sunada, Tomoaki Niiyama, Kazutaka Kanno, Rin Nogami, André Röhm, Takato Awano, and Atsushi Uchida

A new training technique could increase the number of physical systems that could serve as AI platforms.

Phys. Rev. Lett. 134, 017301 (2025)

Analog computation, Physics of computation, Artificial neural networks, High dimensional systems, Nonlinear time-delay systems, Chaos & nonlinear dynamics, Neural network simulations

Passive Defect Driven Morphogenesis in Nematic Membranes

Research article | Biological fluid dynamics | 2025-01-07 05:00 EST

D. J. G. Pearce, C. Thibault, Q. Chaboche, and C. Blanch-Mercader

Orientational order is a common feature of many biological and synthetic materials. Topological defects are discontinuities in this order that are often coupled to geometric features of the materials. Here, we study the equilibrium shapes of fluid membranes featuring a \(+1\) topological defect as a model for morphogenesis. We show, through simulation and analytic calculation, that the membrane can spontaneously deform toward a conical shape with a defect at its apex. We show that the relative stability of the deformation is controlled by the balance of the elastic parameters. When boundary constraints are introduced, we observe three distinct modes of deformation. These deformation modes take advantage of the way in which splay, twist, and bend distortions of the director field can be exchanged on a curved surface. Finally, we demonstrate inverted solutions. Our findings demonstrate a mechanism for passive defect driven morphogenesis as well as the fusion of \(+1/2\) topological defect pairs on deformable surfaces.

Phys. Rev. Lett. 134, 018402 (2025)

Biological fluid dynamics, Morphogenesis, Surface-driven phase separation, Biological liquid crystals, Nematic liquid crystals