The calculation of thermal conductivity in insulating solids at temperatures below the Debye temperature is problematic, due to the breakdown of classical and semiclassical approaches. In this Letter, we present a fully nonperturbative quantum methodology to compute thermal conductivity based on path integral Monte Carlo (PIMC) simulations combined with the Green-Kubo linear response theory. The method is applied to rare gas solids modeled by a Lennard-Jones potential, paradigmatic systems where quantum effects strongly affect both thermodynamic and transport properties. From PIMC simulations, we obtain the temperature-dependent phonon frequencies, lifetimes, and specific heat. From the imaginary time correlations of the energy current, we extract the thermal transport coefficients based on a physically motivated prior. We show that the experimentally observed increase of the thermal conductivity of argon and neon at low temperatures cannot be explained within a Peierls-Boltzmann framework using phonon linewidths at equilibrium. In contrast, a distinct transport lifetime emerges from the analysis of heat-current correlations. Our results demonstrate that quantum Monte Carlo methods provide a robust, nonperturbative framework to investigate heat transport in insulating solids, beyond the limits of classical molecular dynamics without relying on perturbative or semiclassical approximations.

Previous studies of incommensurate systems concluded that their critical scaling is sensitively dependent on the irrational, $\alpha$, which determines the incommensuration. Contrary to this belief, in the canonical Harper-Hofstadter model, we show there is universal $\alpha$-independent scaling for almost all $\alpha$. This critical scaling is characterized by non-power-law time-length scaling $t\sim r^{\zeta \log \log r}$. We demonstrate this in the superfluid fraction of a Bose gas, and the specific heat of a Fermi gas. This scaling is generic of a broad class of generalized Harper-Hofstadter models. The $\alpha$-independent scaling emerges as the number theoretic properties of almost all irrational numbers are statistically identical (à la Gauss-Kuzmin statistics). Consequently, we conjecture similar $\alpha$-independent scaling applies in incommensurate models more generally.

In crystalline solids, disorder breaks translational symmetry and obscures $\mathit{k}$-resolved Bloch states, limiting an accurate description of wave-function-based observables. In this Letter, we present a method that unfolds not only the band structures but also the corresponding Bloch states in disordered systems, going beyond conventional band-unfolding techniques. As a prototype application, we study defective graphene and demonstrate the capabilities by capturing key wave-function-level responses, including disorder-driven redistribution of Berry curvature.

It is widely believed that in the adiabatic limit the Fermi liquid state of an electron-phonon system, described by Migdal-Eliashberg theory, remains stable until the dressed phonon softens. Our variational and analytic analysis of the prototypical Holstein model shows that, in a wide range of fillings both in 3D and 2D, a polaronic/bipolaronic state emerges before phonon softening; at small filling in 3D this happens already at weak coupling. We show that a polaronic/bipolaronic state emerges, upon increasing coupling, via an intermediate pseudogap-type mixed state, in which some fermions retain Fermi liquid behavior, yet Luttinger’s theorem is violated. At even larger couplings the density of states gradually approaches its form in the atomic limit.

A single Landau level (LL) dressed with periodic electrostatic potentials can realize a plethora of interacting topological phases where the Hall conductivity generally does not equal to the LL filling factor. Their physics can be captured by a new family of flat topological bands: decorated Landau levels (dLLs) from imposing an electrostatic delta potential lattice within a single LL. With $p/q$ magnetic fluxes per unit cell, there are $q$ dispersive bands and $p-q$ zero-energy bands forming the dLLs. When the electrostatic potential strength dominates the electron-electron interaction, band mixing is suppressed and the dispersion bands consist of “localized states” with vanishing total Chern number. Nevertheless, these dispersive bands can have highly nontrivial Berry curvature distribution and even nonzero Chern numbers when $q>1$. Interestingly, even in the limit of large short-range interaction, band mixing between dLL and dispersive bands can be strongly suppressed at low filling factor, leading to robust topological phases within the dLLs stabilized by the one-body potential. The dLLs and the associated dispersive bands can serve as minimal theoretical models for correlated physics in lattice or moiré systems; they are also highly tunable experimental platforms for realizing rich phase diagrams of exotic 2D quantum fluids.

We demonstrate that stacking topologically trivial layers, under enforced symmetry restrictions, yields emergent topological phases with protected boundary states. Remarkably, the number of layers itself acts as a topological switch, enabling the system to host topological bound states in the continuum (BICs). Analytically, we reveal that an odd-layer configuration not only renders the spectrum gapless but also supports BICs protected by interlayer reflection symmetry. Combined with entanglement-spectrum calculations, this confirms that odd-layer systems indeed support topological BICs. We provide experimental confirmation of these topological states in stacked acoustic lattices. Our findings establish a previously overlooked pathway to topology and demonstrate a readily applicable strategy for realizing exotic states in a wide range of artificial material systems.

Stochastic search processes are a fundamental part of natural and artificial systems. In such settings, the number of searchers is rarely constant: new agents may be recruited while others can abandon the search. Despite the ubiquity of these dynamics, their combined influence on search efficiency remains unexplored. Here we present a general framework for stochastic search in which independent agents progressively join and leave the process, a mechanism we term “dynamic redundancy and mortality” (DRM). Under minimal assumptions on the underlying search dynamics, this framework yields exact first-passage time statistics. It further reveals surprising connections to stochastic resetting, including a regime in which the resetting mean first-passage time emerges as a universal lower bound for DRM, as well as regimes in which DRM search is faster. We illustrate our results through a detailed analysis of one-dimensional Brownian DRM search. Altogether, this Letter provides a rigorous foundation for studying first-passage processes with a fluctuating number of searchers, with direct relevance across physical, biological, and algorithmic systems.

While molecular conformational changes significantly influence drop pinch-off, the governing mechanisms by which conformational evolution reshapes capillary-driven breakup remain elusive. Here, we isolate the role of conformation using charge regulation to drive conformational transitions in weak polyelectrolytes. We demonstrate that dissociation-driven chain expansion and counterion-mediated screening compete to generate nonmonotonic pinch-off dynamics. Furthermore, a slip-dominated intermediate thinning regime is identified, which is suppressed by concentration-dependent topological constraints. These results establish a physical picture in which conformation reorganizes pinch-off dynamics, while topological constraints select the route to breakup.

Many animals exhibit remarkable regenerative abilities, yet the mechanical processes that drive large-scale tissue reshaping remain challenging to characterize. Direct measurements of stress during such remodeling are difficult, while changes in morphology are readily observed. Motivated by wound healing in Clytia jellyfish, we introduce a theoretical framework that infers mechanical stress directly from shape evolution. We model the transformation as a morphoelastic process in quasi-two-dimensional geometry and exploit conformal mappings to obtain analytical expressions for the stress distribution. This data-driven approach provides a general method to connect observed shapes with the underlying mechanics of regeneration, offering a quantitative framework to study morphogenesis.

In the presence of a weak gravitational wave (GW) background, astrophysical binary systems act as high-quality resonators, with efficient transfer of energy and momentum between the orbit and a harmonic GW leading to potentially detectable orbital perturbations. In this Letter, we develop and apply a novel modeling and analysis framework that describes the imprints of GWs on binary systems in a fully time-resolved manner to study the sensitivity of lunar laser ranging, satellite laser ranging, and pulsar timing to both resonant and nonresonant GW backgrounds. We demonstrate that optimal data collection, modeling, and analysis lead to projected sensitivities that are orders of magnitude stronger than previously appreciated, opening up a new possibility for probing the physics-rich but notoriously challenging-to-access $\mathrm{\mu }\mathrm{Hz}$ frequency band. This improvement arises from retaining accumulated orbital dephasing in the measured residual and scales quadratically with the ratio of the observing time to the unperturbed binary period, up to eccentricity-dependent factors. We also discuss improved prospects for the detection of the stochastic fluctuations of ultralight dark matter, which may analogously perturb the binary orbits.

Using $(10087\pm 44)\times {10}^{6}J/\psi$ events collected with the BESIII detector, we study the semileptonic decay ${\mathrm{\Xi }}^{-}\to \mathrm{\Lambda }{e}^{-}{\overline{\nu }}_e$ for the first time at an electron-positron collider. The absolute branching fraction is determined for the first time to be $(3.60\pm 0.40_{\mathrm{stat}}\pm 0.10_{\mathrm{syst}})\times {10}^{-4}$, which is 3.9 standard deviations below the world average. In addition, using an 11-dimensional angular analysis, the axial-vector to vector coupling $g_{\text{av}}$ is determined to be $0.18\pm 0.07_{\mathrm{stat}}\pm 0.01_{\mathrm{syst}}$. These results are used to test various SU(3)-flavor effective models. Under the SU(3)-flavor symmetry limit, the axial charge is found to be $g_A^H=0.22\pm 0.08_{\mathrm{stat}}\pm 0.02_{\mathrm{syst}}$. Despite using only 5% of the statistics of previous experiments, this analysis achieves a comparable precision for the axial charge.

We map the phase diagram of a two-mode atom-molecule Bose-Einstein condensate with Fano-Feshbach and coherent three-body recombination (cTBR) terms. The standard second-order phase transition observed as the molecular energy is tuned through the Fano-Feshbach resonance is replaced by a first-order transition when cTBR becomes prominent, due to a double-well structure in the free energy landscape. This transition is associated with atom-molecule entanglement, bistability, and molecular metastability. Our results establish cTBR as a powerful knob for quantum state engineering and control of reaction dynamics in ultracold chemistry.

Quantum spin liquids are elusive long-range entangled states. Motivated by experiments in Rydberg quantum simulators, recent excitement has centered on the possibility of dynamically preparing a state with quantum spin-liquid correlations even when the ground-state phase diagram does not exhibit such a topological phase. Understanding the microscopic nature of such quantum spin “lake” states and their relationship to equilibrium spin-liquid order remains an essential question. Here, we extend the use of approximately symmetric neural quantum states for real-time evolution and directly simulate the dynamical preparation in systems of up to $N=384$ atoms. We analyze a variety of spin-liquid diagnostics as a function of the preparation protocol and optimize the extent of the quantum spin lake thus obtained. In the optimal case, the prepared state shows spin-liquid properties extending over half the system size, with a topological entanglement entropy plateauing close to $\gamma =\ln 2$. We extract two physical length scales, ${\lambda }_e$ and ${\xi }_m$, which constrain the extent of the quantum spin lake $\ell$ from above and below.

Acoustic levitation enables noncontact manipulation using sound waves. While conventional methods entrap particles at pressure nodes (zero-pressure region surrounded by high pressure), we demonstrate stable acoustic levitation and translation in midair within a high-pressure axial core of a zero-order Bessel beam for the first time. The trap operates at a long working distance, up to 397 mm ($46.6\lambda$), supports simultaneous multiparticle levitation, and maintains stability over obstacles. Our work establishes a new paradigm for single-sided acoustic manipulation in midair.

We investigate the mechanisms involved in the thermomigration of interstitial hydrogen in metals. Using irreversible thermodynamics, we develop a comprehensive mechanistic model to capture the controlling effects. Crucially, through validation against published experimental data, our results demonstrate that an electron-wind effect plays a significant role, particularly for materials in which the thermomigration direction matches the heat flux. These findings provide new insights into the factors that affect the localization of solutes in metals. Moreover, our results indicate that atomistic models may be inadequate for detailed thermomigration studies due to the omission of electronic effects.

Random walkers usually diffuse according to Fick’s law. On average, they move down the gradient of their concentration and, in the absence of external force, tend to distribute themselves uniformly. In some experiments, however, this familiar notion is at odds with observation. Sand grains, for instance, gather along the nodal lines of a vibrated elastic plate to form a Chladni figure, thus accumulating where fluctuations are weak—a fact that escapes the reach of Fick’s law. On theoretical grounds, Büttiker [Transport as a consequence of state-dependent diffusion, Z. Phys. B Condens. Matter 68, 161 (1987)] and Landauer [Motion out of noisy states, J. Stat. Phys. 53, 233 (1988)] proposed that particles submitted to a nonuniform temperature field would indeed gather where the temperature is low. They also predicted that, in the presence of a potential force, a nonuniform temperature could drive a steady current of particles, powered only by noise. Here, we present an experimental realization of these phenomena in a macroscopic system, which confirms the quantitative predictions of Büttiker.

Understanding the thermal behavior of quantum many-body pure states is one of the most fundamental issues in quantum thermodynamics. It is widely known that typical pure states yield vanishing work, just as thermal states do, when one restricts to local operations that cannot access correlations among subsystems. However, it remains unclear whether this equivalence to thermal states persists under local operations and classical communication (LOCC), where classically accessible correlations can be exploited for work extraction. In this Letter, we establish criteria for determining whether many-body pure states remain equivalent to thermal states even under LOCC, and show that this thermal equivalence is governed by their multipartite quantum correlation structure. We show that states with asymptotically maximal multipartite entanglement, such as Haar-random states, cannot yield extensive work under LOCC, whereas some states with limited multipartite entanglement, such as constant-degree graph states, allow extensive work extraction despite being locally indistinguishable from thermal states. Thus, our Letter provides a refined operational notion of thermal equivalence beyond the traditional local regime, which is becoming increasingly important due to the recent expansion of experimentally accessible operations.