Physical Review X最新文献

{"title":"Exact Nematic and Mixed Magnetic Phases Driven by Competing Orders on the Pyrochlore Lattice","authors":"Niccolò Francini,Lukas Schmidt,Lukas Janssen,Daniel Lozano-Gómez","doi":"10.1103/vwx8-mdtw","DOIUrl":"https://doi.org/10.1103/vwx8-mdtw","url":null,"abstract":"Pyrochlore magnets are a paradigmatic example of three-dimensional frustrated systems and provide an excellent platform for studying a variety of exotic many-body phenomena, including spin liquids, nematic phases, fragmentation, and order by disorder. In recent years, increasing attention has been devoted to bilinear spin models on this lattice, where multiple magnetic phases can be degenerate in energy, often stabilizing unconventional magnetic states. In this work, we focus on one such model, parametrized by the interaction coupling J z ± , which defines a line in parameter space corresponding to the phase boundary between three distinct magnetic phases. Using a combination of analytical and numerical methods, we show that this model exhibits an order-by-disorder mechanism at low temperatures, giving rise to a magnetic phase. This realizes a q = 0 long-range-ordered phase in a pyrochlore magnet characterized by two distinct order parameters, which we denote as the A 2 ⊕ ψ 2 phase. Furthermore, at J z ± = 1 / 2 , the model acquires a subextensive number of discrete symmetries, which preclude the stabilization of conventional long-range order and instead lead to the emergence of a novel nematic phase. We characterize this nematic phase, describe how its ground-state configurations are constructed, and analyze its stability at higher temperatures and under small deviations from J z ± = 1 / 2 .","PeriodicalId":20161,"journal":{"name":"Physical Review X","volume":"1 1","pages":""},"PeriodicalIF":12.5,"publicationDate":"2026-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149020545","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Certifying localizable quantum properties with constant sample complexity","authors":"Anonymous","doi":"10.1103/rkl6-hfrn","DOIUrl":"https://doi.org/10.1103/rkl6-hfrn","url":null,"abstract":"","PeriodicalId":20161,"journal":{"name":"Physical Review X","volume":"11 1","pages":""},"PeriodicalIF":12.5,"publicationDate":"2026-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149020516","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exponential gain in clock precision using quantum correlated ticks","authors":"Anonymous","doi":"10.1103/ftym-1117","DOIUrl":"https://doi.org/10.1103/ftym-1117","url":null,"abstract":"","PeriodicalId":20161,"journal":{"name":"Physical Review X","volume":"26 1","pages":""},"PeriodicalIF":12.5,"publicationDate":"2026-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149020517","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pomeranchuk Instability Induced by an Emergent Higher-Order Van Hove Singularity on the Distorted Kagome Surface of\u0000 \u0000 \u0000 \u0000 \u0000 Co\u0000 \u0000 \u0000 3\u0000 \u0000 \u0000 \u0000 \u0000 Sn\u0000 \u0000 \u0000 2\u0000 \u0000 \u0000 \u0000 \u0000 S\u0000 \u0000 \u0000 2\u0000 \u0000 \u0000 \u0000 ","authors":"Pranab Kumar Nag,Rajib Batabyal,Julian Ingham,Noam Morali,Hengxin Tan,Jahyun Koo,Jean Souza,Moshe Haim,Armando Consiglio,Enke Liu,Raquel Queiroz,Ronny Thomale,Binghai Yan,Claudia Felser,Nurit Avraham,Haim Beidenkopf","doi":"10.1103/2jst-psds","DOIUrl":"https://doi.org/10.1103/2jst-psds","url":null,"abstract":"Materials hosting flat bands at the vicinity of the Fermi level promote exotic symmetry broken states. Common to many of these are Van Hove singularities at saddle points of the dispersion or even higher-order Van Hove singularities (HOVHSs) where the dispersion is flattened further. The band structure of kagome metals hosts both a flat band and two regular saddle points flanking a Dirac node. We investigate the kagome ferromagnetic metal Co 3 Sn 2 S 2 using scanning tunneling spectroscopy. We identify a new mechanism by which a triangular distortion on its kagome Co 3 Sn surface termination considerably flattens the saddle point dispersion and induces an isolated HOVHS with algebraically divergent density of states pinned to the Fermi energy. The distortion-induced HOVHS precipitates a Pomeranchuk instability of the Fermi surface, resulting in the formation of a series of nematic electronic states. We visualize the nematic order across an energy shell of about 100 meV in both real, reciprocal, and momentum spaces, as a cascade of wave function distributions which spontaneously break the remaining rotational symmetry of the underlying distorted kagome lattice, without generating any additional translational symmetry breaking. It signifies the spontaneous removal of a subset of saddle points from the Fermi energy to lower energies. By tracking the electronic wave function structure across the deformed Fermi surface, we further identify a charge pumpinglike evolution of the wave function center of mass. The mechanism we find for the generation of higher-order saddle points under a kagome distortion may be common to other kagome materials, and potentially other lattice structures, suggesting a generic new avenue for inducing unconventional electronic instabilities toward exotic states of matter.","PeriodicalId":20161,"journal":{"name":"Physical Review X","volume":"1 1","pages":""},"PeriodicalIF":12.5,"publicationDate":"2026-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149020518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spin-resolved microscopy of\u0000 \u0000 \u0000 \u0000 87\u0000 \u0000 \u0000 Sr SU(N) Fermi-Hubbard systems","authors":"Anonymous","doi":"10.1103/v9sh-cq7r","DOIUrl":"https://doi.org/10.1103/v9sh-cq7r","url":null,"abstract":"","PeriodicalId":20161,"journal":{"name":"Physical Review X","volume":"41 1","pages":""},"PeriodicalIF":12.5,"publicationDate":"2026-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149020519","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reversibility, Chaos, and Attractors in Periodically Sheared Elastic Filaments","authors":"Francesco Bonacci,Brato Chakrabarti,Olivia du Roure,Anke Lindner,David Saintillan","doi":"10.1103/84g7-fmcv","DOIUrl":"https://doi.org/10.1103/84g7-fmcv","url":null,"abstract":"The dynamics of flexible filaments in flow underpin a broad range of biological and soft-matter phenomena, yet their response to time-dependent forcing remains poorly understood. Here, we investigate the long-time dynamics of Brownian inextensible elastic filaments subjected to strong oscillatory shear by combining microfluidic experiments on actin filaments with numerical simulations based on a fluctuating Euler-Bernoulli elastica model in a viscous fluid. As the oscillation period increases, the interplay of flow-induced buckling and thermal fluctuations drives a transition away from reversible rigid-body dynamics. Remarkably, the time-glide symmetry of oscillatory shear gives rise to two coexisting symmetry-related dynamical attractors, between which stochastic fluctuations induce intermittent switching events. These attractors correspond to cyclic states in which filaments become nearly straight and flow aligned at full periods while adopting buckled conformations at half periods. Individual filaments spontaneously select one attractor but intermittently hop to the other, producing alternating episodes of ordered and chaotic dynamics. Our results establish periodically driven Brownian flexible filaments as an experimentally accessible realization of stochastic symmetry breaking, attractor hopping, and intermittency in a minimal nonequilibrium system, and present novel opportunities for the design and control of soft materials under time-dependent flows.","PeriodicalId":20161,"journal":{"name":"Physical Review X","volume":"62 1","pages":""},"PeriodicalIF":12.5,"publicationDate":"2026-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149020521","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Overcoming Intrinsic Material Limitations through Cavity Feedback","authors":"M. Ebrahimi,Y. Huang,V. A. S. V. Bittencourt,A. Rashedi,A. Metelmann,J. P. Davis","doi":"10.1103/pbbp-bz28","DOIUrl":"https://doi.org/10.1103/pbbp-bz28","url":null,"abstract":"Magnons, the quanta of spin waves, have significant potential for use in modern technologies, especially when they are strongly coupled to another mode for readout and control. Although magnons strongly interact with microwave photons via the magnetic-dipole interaction to form hybrid cavity-magnon polariton modes, the magnon-phonon interaction in micrometer-sized ferromagnetic spheres is typically weak, which is further aggravated by the large polariton linewidths dominated by the magnon dissipation. The material-limited magnon dissipation rate in particular has been regarded as an unavoidable limitation in these systems. Here, we surpass this long-standing limitation by implementing an active microwave feedback loop to suppress the linewidth of cavity-magnon polaritons and reduce their effective decay rate below the magnon-limited linewidth, thereby enhancing the polariton-phonon cooperativity from C ≃ 1 to C ≃ 300 . As a key milestone, we achieved normal-mode splitting between a cavity-magnon polariton and a mechanical mode, providing direct evidence of three-mode hybridization among photons, magnons, and phonons. Our results establish feedback as a general route to accessing strong-coupling regimes in systems previously thought to be limited by material properties and hence open new opportunities for coherent control in hybrid quantum systems.","PeriodicalId":20161,"journal":{"name":"Physical Review X","volume":"29 1","pages":""},"PeriodicalIF":12.5,"publicationDate":"2026-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149020520","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Emergent Altermagnetism at Surfaces of Antiferromagnets: Full Symmetry Classification and Material Identification","authors":"Colin Lange,Rodrigo Jaeschke-Ubiergo,Atasi Chakraborty,Xanthe H. Verbeek,Libor Šmejkal,Jairo Sinova,Alexander Mook","doi":"10.1103/6j6l-kb6x","DOIUrl":"https://doi.org/10.1103/6j6l-kb6x","url":null,"abstract":"We demonstrate the emergence of altermagnetism at the surfaces of antiferromagnets, vastly expanding the number of material candidates with altermagnetic characteristics and establishing a route towards two-dimensional altermagnetism through surface-induced symmetry breaking. We do so by developing a formalism that fully classifies all surface magnetic states and identifies altermagnetic surface spin groups that can arise at the surfaces of antiferromagnets. We use this formalism to identify over 150 antiferromagnetic entries from the MAGNDATA database with at least one altermagnetic surface, often times with multiple such surfaces in the same material, and clarify the role of surface roughness and terraces. We illustrate this emergent phenomenon in a realistic Lieb lattice-based minimal model and present calculations on two representative material candidates, NaMnP and FeGe 2 , exhibiting d -wave and g -wave surface altermagnetism, respectively. Our theory naturally resolves the contradiction of recent experimental reports of d -wave spin splitting from ARPES measurements on metallic Lieb lattice compounds such as KV 2 Se 2 O that have been shown to be antiferromagnetic in the bulk. Hence, we establish a new paradigm for generating effectively two-dimensional altermagnetism by functionalizing the abundant material class of collinear antiferromagnets as viable platforms for controlled surface altermagnetism.","PeriodicalId":20161,"journal":{"name":"Physical Review X","volume":"8 1","pages":""},"PeriodicalIF":12.5,"publicationDate":"2026-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148923402","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geometrically Frustrated Quadrupoles on the Pyrochlore Lattice and Generalized Spin Liquids","authors":"Kristian Tyn Kai Chung,Sylvain Petit,Julien Robert,Paul McClarty","doi":"10.1103/vl1q-p27w","DOIUrl":"https://doi.org/10.1103/vl1q-p27w","url":null,"abstract":"As an instance of geometrical frustration with nonmagnetic degrees of freedom, we explore the physics of local spin S ≥ 1 moments on the pyrochlore lattice that interact via pure quadrupolar couplings. In the presence of spin-orbit coupling, there are nine allowed couplings between nearest-neighbor quadrupoles. We determine the semiclassical phases and survey the phase diagram of the model. One may view the Hamiltonian as being composed of two copies of the well-studied dipolar model with couplings between the copies, and we find that each easy-plane dipolar phase has two quadrupolar counterparts. As geometrical frustration is important over broad swathes of the parameter space, there are many classical quadrupolar liquids and regions with order-by-disorder selection of discrete states. Order by disorder with quadrupoles admits cubic terms in the Landau theory whose effects appear in Monte Carlo simulations and flavor-wave calculations for fixed spin S . We showcase a number of examples of quadrupolar spin liquids, including one realizing a rank-3 symmetric tensor gauge theory exhibiting sixfold pinch point singularities. We discuss remarkable differences between the quadrupolar physics of different spin quantum number. We also discuss connections to the non-Kramers rare earth pyrochlore materials.","PeriodicalId":20161,"journal":{"name":"Physical Review X","volume":"69 1","pages":""},"PeriodicalIF":12.5,"publicationDate":"2026-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148923426","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effective Ionic Valence and Local Magnetic Moment in Kagome Superconductors","authors":"Ruoshi Jiang,Zi-Jian Lang,Yuzki Oey,Andrea Capa Salinas,Stephen D. Wilson,Yongwei Li,Ilya Shipulin,Yiwen Zhang,Deng Hu,Zhiwei Wang,Hans-Henning Klauss,Zurab Guguchia,Vadim Grinenko,Wei Ku","doi":"10.1103/t5nf-jksr","DOIUrl":"https://doi.org/10.1103/t5nf-jksr","url":null,"abstract":"In order to understand the unexpected similarity and the correlated behavior in kagome superconductor families A V 3 Sb 5 ( A = K , Rb , Cs ) and A Ti 3 Bi 5 ( A = Rb , Cs ), we investigate the Hartree-scale local electronic structure of these systems. Our result indicates that V and Ti ions are both of 2 + valence such that the corresponding itinerant carrier densities are similar, and the difference in electron count is instead reflected in their quantum fluctuating ionic magnetic moments. However, due to the frustrated lattice geometry of these materials, such local moments are difficult to experimentally observe via standard probes. For verification, we systematically introduce nonmagnetic Sn impurities to locally relieve the geometric frustration and experimentally demonstrate the existence of well-defined local magnetic moments via magnetic susceptibility and muon spin rotation or relaxation ( μ SR ) measurements. All experiments discover a systematic increase of magnetic susceptibility upon increasing nonmagnetic impurity level. Our discovered ionic moments suggest a paradigm shift from the existing itinerant carrier-only picture to one incorporating strong correlation from local ionic spins. The associated interatomic and local-itinerant correlations offer a solid ground for the emergence of the observed rich correlated behavior in this new family of superconducting materials.","PeriodicalId":20161,"journal":{"name":"Physical Review X","volume":"36 1","pages":""},"PeriodicalIF":12.5,"publicationDate":"2026-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148923403","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}