An electric double-layer capacitor (EDLC) stores energy by modulating the spatial distribution of ions in the electrolytic solution that it contains. We determine the mean-field timescales for planar EDLC relaxation to equilibrium after a potential difference is applied. We tackle first the fully symmetric case, where positive and negative ionic species have the same valence and diffusivity, and then the general, more complex, asymmetric case. Depending on the applied voltage and salt concentration, different regimes appear, revealing a remarkably rich phenomenology relevant for nanocapacitors.

We study the stability of ultracompact boson stars admitting light rings combining a perturbative analysis with $3+1$ numerical-relativity simulations with and without symmetry assumptions. We observe excellent agreement between all perturbative and numerical results, which uniformly support the hypothesis that this family of black-hole mimickers is separated into stable and unstable branches by extremal-mass configurations. This separation includes, in particular, thin-shell boson stars with light rings located on the stable branch, which we conclude to represent long-term stable black-hole mimickers.

We explore the potential of precision spectroscopy of heavy exotic atoms where electrons are substituted by negative hadrons to detect new force carriers with hadronic couplings. The selected transitions are unaffected by nuclear contact terms, thus enabling highly accurate calculations using bound-state QED, provided that the nuclear polarization is under control. Alternatively, we demonstrate that the dipole polarizability, a fundamental property of nuclei, can be extracted from the spectroscopy of exotic atoms in a novel way by combining two transitions while maintaining high sensitivity to new physics. Based on existing data, we extracted world-leading bounds on mediator masses ranging from 0.1 to 10 MeV for two benchmark models and show that forthcoming experiments could enhance the sensitivity to new physics by 2 orders of magnitude.

When an external parameter drives a system across a quantum phase transition at a finite rate, work is performed on the system and entropy is dissipated, due to creation of excitations via the Kibble-Zurek mechanism. Although both the adiabatic and sudden-quench limits have been studied in detail, the quantum work statistics along the crossover connecting these limits has largely been an open question. Here, we obtain exact scaling functions for the work statistics along the full crossover from adiabatic to sudden-quench limits for critical quantum impurity problems, by combining linear response theory, conformal field theory, and the numerical renormalization group. These predictions can be tested in charge-multichannel Kondo quantum dot devices, where the dissipated work corresponds to the creation of nontrivial excitations such as Majorana fermions or Fibonacci anyons.

Measurement-based quantum repeaters employ entanglement distillation and swapping across links using locally prepared resource states of minimal size and local Bell measurements. In this Letter, we introduce a systematic protocol for measurement-based entanglement distillation and its application to repeaters that can leverage any stabilizer code. Given a code, we explicitly define the corresponding resource state and derive an error-recovery operation based on all Bell measurement outcomes. Our approach offers deeper insights into the impact of resource state noise on repeater performance while also providing strategies for efficient preparation and fault-tolerant preservation of resource states. As an application, we propose a measurement-based repeater protocol based on quantum low-density parity-check (QLDPC) codes, enabling constant-yield Bell state distribution over arbitrary distances. Numerical simulations identify a fault-tolerant threshold on the total physical error per repeater segment—including errors on resource states, remotely generated Bell states, and Bell measurements—and confirm that increasing the QLDPC code size further suppresses the logical error while maintaining a fixed encoding rate. This Letter establishes a scalable backbone for future global-scale fault-tolerant quantum networks.

We present a fault-tolerant Bell-pair distillation scheme achieving constant overhead through high-rate quantum low-density parity-check (qLDPC) codes. Our approach maintains a constant distillation rate equal to the code rate while requiring no additional overhead beyond the physical qubits of the code. Full circuit-level analysis demonstrates fault-tolerance for input Bell-pair infidelities below a threshold $\sim 10\%$, readily achievable with near-term capabilities. Unlike previous proposals, our scheme keeps the output Bell pairs encoded in qLDPC codes at each node, eliminating unencoding overhead and enabling direct use in distributed quantum applications through recent advances in qLDPC computation. These results establish qLDPC-based distillation as a practical route toward resource-efficient quantum networks and distributed quantum computing.

Scaling quantum computation is a crucial challenge for practical applications, hindered by the inherent errors and noises in real-world quantum systems. The quantum modular architecture offers a possible solution, where smaller quantum modules are individually constructed and assembled into a larger architecture. In this architecture, the nonlocal quantum gates are the building blocks; until now, it has remained challenging for practical applications to implement a nonlocal quantum gate with the memory modules under deterministic and room-temperature conditions, due to intrinsic probability and hardware complexity. Here, we propose and demonstrate a scheme to deterministically implement a nonlocal quantum gate between the room-temperature memory modules. The key technologies include cavity-enhanced atomic modules, two of which are connected by a single pair of distributed entangled optical modes and real-time mutual feedforward controls. The nonlocal quantum nondemolition gate between two room-temperature memory modules is deterministically demonstrated with different input coherent states, and the quantum nature is confirmed by outputting entangled atomic modules. Our results illustrate the functionality and feasibility of nonlocal quantum gate and may have potential applications in modular quantum information processing.

Relativistic structured spin-polarized (SSP) particle beams, characterized by polarization structures, are of critical importance in a wide range of applications, such as material properties investigation, imaging, and information storage. However, the generation of relativistic SSP beams faces significant challenges. Here, we put forward a novel method for generating relativistic SSP lepton beams via employing a state-of-the-art THz source. Building upon our foundational work on velocity-matched spin rotation in dielectric-lined waveguides [Phys. Rev. Lett. 134, 075001 (2025)], we present the first demonstration of spin-polarization mode matching—a novel mechanism that establishes a direct relation between waveguide modes and beam polarization states. This breakthrough enables precise spatial control over spin structures at relativistic energies, generating customizable spin-polarization configurations such as spiderlike, azimuthal, and helical structures. Such SSP beams have the potential to generate high-energy structured photon beams and open a new avenue for research on relativistic structured particle beams, especially in nuclear physics, high-energy physics, materials science, and atomic physics.

We report the nonreciprocal charge transport along the longitudinal and transverse directions in the vortex flow regime of FeSe superconducting films. Clear nonreciprocal signals under an in-plane magnetic field reveal symmetry breaking at the film surfaces, since the crystal structure of FeSe is centrosymmetric. Although the symmetry in such polar superconductors allows the nonreciprocal transverse response under a magnetic field parallel to the electric current, its observation is physically counterintuitive, because vortex motion is not expected in this configuration. We propose that thermally excited (anti)vortices due to the two-dimensional nature of FeSe give rise to the nonreciprocal transverse signals when the mirror symmetry is broken by the in-plane magnetic field.

We report measurements of anisotropic triple-$q$ charge density wave (CDW) fluctuations in the transition metal dichalcogenide $1T\text{−}{\mathrm{TiSe}}_2$ over a large volume of reciprocal space with x-ray diffuse scattering. Above the transition temperature, $T_{\mathrm{CDW}}$, the in-plane diffuse scattering is marked by ellipses which reveal that the in-plane fluctuations are anisotropic. In addition, the out-of-plane diffuse scattering is characterized by rodlike structures which indicate that the CDW fluctuations in neighboring layers are largely decoupled. Our analysis of the diffuse scattering line shapes and orientations suggests that the three charge density wave components contain independent phase fluctuations with a hierarchy of length scales, leading to intricate fluctuation patterns that go beyond the conventional 2D-to-3D crossover picture.

We investigate the evolution of polarized electronic response in trilayer nickelate ${\mathrm{La}}_4{\mathrm{Ni}}_3{\mathrm{O}}_{10}$, reporting a systematic reduction of the incoherent electron continuum across the density wave transition in the $A_{1g}$ and $B_{1g}$ representations. Analysis based on the Fermi surface band curvatures points to quasiparticle coherence in momentum positions with dominant $d_{x^2-y^2}$ orbital character. Our findings establish the symmetry channels and the active role of $d_{x^2-y^2}$ orbitals involved in the density wave formation, offering important insight into the electronic and magnetic correlations in the nickelate.

Characterizing the statistical properties of classical interacting particle systems is a long-standing question. For Brownian particles, the microscopic density obeys a stochastic evolution equation, known as the Dean-Kawasaki equation. This equation remains mostly formal and linearization (or higher-order expansions) is required to obtain explicit expressions for physical observables, with a range of validity not easily defined. Here, by combining macroscopic fluctuation theory with equilibrium statistical mechanics, we provide a systematic alternative to the Dean-Kawasaki framework to characterize large-scale correlations. This approach enables us to obtain explicit and exact results for the large-scale behavior of dynamical observables such as tracer cumulants and bath-tracer correlations in one dimension, both in and out of equilibrium. In particular, we reveal a generic nonmonotonic spatial structure in the response of the bath following a temperature quench. Our approach applies to a broad class of interaction potentials and extends naturally to higher dimensions.

Analyzing 9000 urban areas’ street networks, we identify properties, including extreme betweenness centrality heterogeneity, that typical spatial network models fail to explain. Accordingly we propose a universal, parsimonious, generative model based on a two-step mechanism that begins with a spanning tree as a backbone then iteratively adds edges to match empirical degree distributions. Controlled by a single parameter representing lattice-equivalent node density, it accurately reproduces key universal properties to bridge the gap between empirical observations and generative models.

The persistent dynamics of active particles makes them explore extended portions of an obstacle’s boundary during collisions. From impact to escape, the net applied forces depend on the curvature of the wall and increase in the presence of concave features. Here we systematically investigate the forces exerted by swimming bacteria on microfabricated structures, where the radii of curvature can be varied parametrically. We find that these microsails are propelled with a speed that scales linearly with curvature and is directed from concave to convex side along the axis of symmetry. By solving the collision problem for microswimmers subject to aligning torques at the wall, we show that, despite bacteria rapidly aligning with the surface plane, the resulting force law reduces to that of spherical active particles, with the wall-induced reorientation rate effectively replacing rotational diffusion.

New limits on the axion-nucleon coupling over the axion mass region ${10}^{-24}\le m_a\le 5\times {10}^{-21}\mathrm{eV}$ are derived by reanalyzing data from laboratory measurements on Lorentz and $CPT$ violations. These results establish the first laboratory constraints on the axion-nucleon coupling for axion masses below ${10}^{-22}\mathrm{eV}$. For ${10}^{-22}\le m_a\le 5\times {10}^{-21}\mathrm{eV}$, the results improve upon previous laboratory limits by more than three orders of magnitude, exceeding for the first time the astrophysical limits from supernova SN1987A cooling. For the axion mass range of interest corresponding to ultralow frequencies, the crucial local phase of the axion field is considered. Furthermore, the obtained limits are nearly equivalent to those projected for a recently proposed experiment employing high-intensity neutron beams at the European Spallation Source. For an alternative type of axion-nucleon interaction, the quadratic wind coupling, the constraints exceed the current best results by approximately two orders of magnitude.

The detection of cosmic antideuterons ($\overline{\text{D}}$) at kinetic energies below a few $\mathrm{GeV}/n$ could provide a smoking gun signature for dark matter (DM). However, the theoretical uncertainties of coalescence models have represented so far one of the main limiting factors for precise predictions of the $\overline{\text{D}}$ flux. In this Letter, we present a novel calculation of the $\overline{\text{D}}$ source spectra, based on the Wigner formalism, for which we implement the Argonne $v_{18}$ antideuteron wave function that does not have any free parameters related to the coalescence process. We show that the Argonne-Wigner model excellently reproduces the $\overline{\text{D}}$ multiplicity measured by ALEPH at the $Z$-boson pole, which is usually adopted to tune the coalescence models based on different approaches. Our analysis is based on the pythia 8 Monte Carlo event generator and the state-of-the-art shower algorithm. We succeed, with our model, to reduce the current theoretical uncertainty on the prediction of the $\overline{\text{D}}$ source spectra to a few percent, for $\overline{\text{D}}$ kinetic energies relevant to DM searches with the General Antiparticle Spectrometer and Alpha Magnetic Spectrometer, and for DM masses above a few tens of GeV. This result implies that the theoretical uncertainties due to the coalescence process are no longer the main limiting factor in the predictions. We provide the tabulated source spectra for all the relevant DM annihilation and decay channels and DM masses between 5 and 100 TeV, on the CosmiXs GitHub repository.

We propose a recursive method that makes use of the basic principle of unitarity to calculate the Landau singularities of $n$-point scattering amplitudes directly in kinematic space. For a vast class of Feynman diagrams, the method enables rapid analytic computation of Landau singularities beyond current state-of-the-art technology. This includes new predictions relevant for two- and higher-loop processes in the standard model involving both massive quarks and electroweak particles.