We present a novel strategy to uncover indirect signs of new physics in collider data using the standard model effective field theory (SMEFT) framework, offering notably improved sensitivity compared to traditional global analyses. Our approach leverages genetic algorithms to efficiently navigate the high-dimensional space of operator subsets, identifying deformations that improve agreement with data without relying on prior ultraviolet (UV) assumptions. This enables the systematic detection of SMEFT scenarios that outperform the standard model in explaining observed deviations. We validate the approach on current large hadron collider and large electron-positron collider measurements, perform closure tests with injected UV signals, and assess performance under high-luminosity projections. The algorithm successfully recovers relevant operator subsets and highlights directions in parameter space where deviations are most likely to emerge. Our results demonstrate the potential of SMEFT-based discovery searches driven by model selection, providing a scalable framework for future data analyses.

The presence of dark matter (DM) stands as one of the most compelling indications of new physics in particle physics. Typically, the detection of wavelike DM involves quantum sensors, such as qubits or cavities. The phase of the sensors is usually discarded as the value of the phase itself is not physically meaningful. However, the difference of the phase between the sensors contains the information of the velocity and direction of the DM wind. We propose a measurement protocol to extract this information from the sensors using quantum states. Our method does not require specific experimental setups and can be applied to any type of DM detector as long as the data from the detectors can be taken quantum mechanically. We also show that our method does not spoil the sensitivity of the DM detectors and is superior to the classical method based on the correlations of the DM signals between the detectors.

This Letter introduces a unified emulation framework for studying continuum physics in finite quantum systems. Using a reduced basis method, we construct powerful emulators for the inhomogeneous Schrödinger equation that operate in a combined parameter space of complex energy ($E$) and other inputs ($\mathit{\theta }$). Within the space, the emulators simultaneously perform analytical continuation in $E$—extracting continuum physics from numerically simpler bound-state-like calculations—and interpolate this entire process across $\mathit{\theta }$. This yields a small, non-Hermitian system whose properties (e.g., resonances and scattering observables) can be rapidly predicted for any $\mathit{\theta }$. Crucially, the complex-$E$ emulation provides a pathway to compute continuum observables for complex systems where advanced bound-state methods exist but direct continuum calculations are yet to be developed, while the $\mathit{\theta }$ emulation enables rapid parameter-space exploration and can be adapted to accelerate other existing continuum calculations. Demonstrations with two- and three-body systems highlight the method’s effectiveness and suggest its connection to (near-)optimal rational approximation. This Letter presents the key results, with further details reserved for a companion paper.

The formation of quantized vortices is a unifying feature of quantum mechanical systems, making it a premier means for fundamental and comparative studies of different quantum fluids. Being excited states of motion, vortices are normally unstable towards relaxation into lower energy states. However, here we exploit the driven-dissipative nature of polaritonic fluids of light to create stationary, multiply charged vortices. We measure the spectrum of collective excitations and observe negative energy modes at the core and positive energy modes at large radii. Their coexistence at the same frequency normally causes the dynamical instability, but here intrinsic losses stabilize the system, allowing for phase pinning by the pump on macroscopic scales. We observe generic features of quantized vortices in quantum fluids and other rotating geometries like astrophysical compact objects, opening the way to the study of generic amplification phenomena.

While field-driven electron emission is theoretically understood down to the subcycle regime, its direct experimental temporal characterization using long-wavelength terahertz (THz) fields remains elusive. Here, by driving a graphite tip with phase-stable quasi-single-cycle THz pulses, we reveal distinct subcycle electron emission dynamics including: (i) At a carrier-envelope phase (CEP) zero, spectral peaks scale linearly with THz field strength, characteristic of subcycle emission; (ii) at nearly opposite CEP, dominant deceleration fields generate stationary low-energy peaks. Crucially, we develop a pump-probe-free, direct reconstruction method extracting electron pulse profiles solely from measured energy spectra, obtaining durations from 73.0 to 81.0 fs as the field increases (191–290 kV/cm). Phase-resolved simulations further reveal a 72.8% modulation in the cutoff energy and a near-total (99.7%) suppression of the emission current. This Letter not only validates the field-emisssion theory under THz excitation but also establishes a general framework for the direct temporal characterization of subcycle electron emission, opening pathways for precise electron control in ultrafast electron sources and lightwave nanoelectronics.

Motivated by the recent observations of superconductivity in twisted bilayer ${\mathrm{WSe}}_2$ (${\mathrm{tWSe}}_2$), we theoretically investigate the superconductivity driven by an electronic mechanism. We first demonstrate that the multiband screened Coulomb interaction within the random phase approximation is insufficient to induce observable pairing instability. Nevertheless, by further including the intervalley antiferromagnetic fluctuations, the pairing interaction is substantially enhanced, yielding superconductivity with critical temperature $T_c$ of hundreds of millikelvin at Van Hove singularities. The predicted $T_c$ increases with increasing the displacement field and corresponds to a doubly degenerate $d$-wavelike pairing, which evolves into a topological chiral $d\pm id$ superconductor below $T_c$. The interplay between superconductivity and intervalley antiferromagnetism results in a phase diagram consistent with experimental observations. These findings provide strong support for intervalley fluctuations as the primary pairing glue in ${\mathrm{tWSe}}_2$.

The superconducting diode effect (SDE) is characterized by the nonreciprocity of Cooper-pair motion with respect to current direction. In three-dimensional (3D) materials, SDE results in a critical current that varies with direction, making the effect distinctly observable: the material exhibits superconductivity in one direction while behaving as a resistive metal in the opposite direction. However, in genuinely two-dimensional (2D) materials, the critical current density is theoretically zero, leaving the manifestation of SDE in the 2D limit an intriguing challenge. Here, we present the observation of SDE in a heterostructure composed of the topological insulator ${\text{Bi}}_2{\text{Te}}_3$ and the iron-based superconductor Fe(Se,Te)—a candidate for topological superconductor—where superconductivity is confined to the 2D limit. The observed $I\text{−}V$ characteristics reveal nonreciprocity in the vortex-creep regime, where finite voltages arise due to the 2D nature of superconductivity. Furthermore, our 2D film demonstrates abrupt voltage jumps, influenced by both the current flow direction and the transverse magnetic field direction. This behavior resembles that of 3D materials but, in this case, is driven by the vortex-flow instability, as illustrated by voltage-controlled S-shaped $I\text{−}V$ curves. These results underscore the pivotal role of vortex dynamics in SDE and provide new insights into the interplay between symmetry breaking and two dimensionality in topological insulator/superconductor systems.

Elucidating the kinetics of surface reconstruction is fundamentally important yet inherently challenging due to the complex collective atomic motions occurring across high-dimensional potential-energy landscapes. Here, we combine machine-learning-based molecular dynamics simulations enhanced by well-tempered metadynamics with in situ environmental transmission electron microscopy to directly uncover the critical role of surface titanium diffusion in driving the structural evolution of the ${\mathrm{TiO}}_2(110)\text{−}(1\times 2)$ reconstruction. Under oxygen-deficient conditions, the ${\mathrm{TiO}}_2(110)\text{−}(1\times 2)$ reconstruction remains thermodynamically stable, and surface Ti migration is largely suppressed. In contrast, under oxygen-rich conditions, the surface Ti atomic rows exhibit pronounced splitting and migration, facilitated by the incorporation of additional oxygen atoms that enhance Ti mobility. Our simulations demonstrate that these oxygen-promoted processes can induce structural transformations of the ${\mathrm{TiO}}_2(110)\text{−}(1\times 2)$ reconstruction, resulting in transitions from double-row to single-row or triple-row configurations. These predictions are further validated by experimental observations. This Letter establishes a microscopic mechanism for rutile surface reconstruction kinetics and provides valuable insights for the controlled manipulation of surface structures under varying chemical environments.

In this Letter, we experimentally and theoretically demonstrate an asymmetric elastic bound state in the continuum (BIC) induced by an exceptional point (EP) in an open elastic system. For positive incidence, the characteristic vanishing linewidth of a BIC is observed, whereas it is absent for negative incidence. Notably, the resulting nontrivial quasi-BIC (qBIC) exhibits perfect energy localization and extremely high quality factors ($Q$), while for the negative direction, most of the energy is radiated, yielding $Q$ close to zero. By modulating the system’s loss, this nontrivial qBIC mode can approximately evolve into a genuine BIC. Remarkably, the nontrivial mode can also coalesce into an EP BIC, where the energy is entirely localized within the non-Hermitian resonator system with asymmetric loss. Our Letter establishes a nontrivial connection between two seemingly unrelated concepts—BICs and EPs—and reveals a novel physical mechanism for achieving asymmetric high $Q$ and strong energy localization, offering new opportunities for high-performance elastic-wave devices.

The quantum Hall effect is one of the most fundamental quantum phenomena in condensed matter physics, and via tuning the quantum Hall states (QHSs), the evolution of band topologies and electron correlations can be investigated and revealed therein. However, for the vast majority of QHS systems, even- and odd-integer quantized plateaus coexist and cannot be effectively regulated. Here, we demonstrate field-effect-tunable even-odd transition of QHSs in a fixed two-unit-cell-thick (2-uc-thick) ${\mathrm{Bi}}_2{\mathrm{O}}_2\mathrm{Se}$ film, which is unlike irreversible thickness-controlled approaches [J. Wang et al., Even-integer quantum Hall effect in an oxide caused by a hidden Rashba effect, Nat. Nanotechnol. 19, 1452 (2024)]. Only even-integer quantized plateaus are observed in the 2-uc-thick epitaxial film on ${\mathrm{SrTiO}}_3$ when the quantum oscillations show degenerated spin splitting under positive gate voltages. In contrast, the simultaneous emergence of even- and odd-integer QHSs is achieved under negative gate voltages, accompanied with significant spin splitting. Theoretical calculations reveal that this reversible switching stems from gate-controlled inversion symmetry breaking that modulates the splitting of Landau levels. This Letter demonstrates the significant tunability of electrostatic gating in altering inversion symmetry and modulating electron correlations in Rashba-type 2-uc-thick ${\mathrm{Bi}}_2{\mathrm{O}}_2\mathrm{Se}$, enabling dynamic control of QHSs parity without structural changes, thereby extending the potential applications to fractional statistics and spintronics.

The fractional quantum Hall state (FQHS) observed in the lowest Landau level at filling factor $\nu =1/2$ in wide quantum wells has been enigmatic for decades because the two-dimensional electron system (2DES) has a bilayer charge distribution but with significant interlayer tunneling. Of particular interest is whether the $1/2$ FQHS in this system has a one-component (1C) or two-component (2C) origin; these are typically identified as the Pfaffian (non-Abelian) or the ${\mathrm{\Psi }}_{331}$ (Abelian) FQHSs, respectively. We report here our experimental study of the evolution of the correlated states of an ultrahigh-quality 2DES confined to a 72.5-nm-wide GaAs quantum well. At the lowest densities, the 2DES displays only odd-denominator FQHSs, and the ground state at $\nu =1/2$ is a composite fermion Fermi sea. As the density is increased, an FQHS emerges at $\nu =1/2$, and becomes very strong. In a finite density range where the $1/2$ FQHS is strongest, we also observe its daughter FQHSs at $\nu =8/17$ and $7/13$, consistent with the theoretically expected daughter states of a Pfaffian $1/2$ FQHS. At the highest densities, the 2DES becomes 2C, signaled by the emergence of a bilayer Wigner crystal state and the transitions of FQHSs flanking $\nu =1/2$. The $1/2$ FQHS remains robust near this transition and, notably, its charge transport energy gap exhibits an upward cusp with a maximum value of about 6 K on the 1C side of the transition; this is the largest gap reported for any even-denominator FQHS. Our observation of the transition of the 2DES ground states near $\nu =1/2$ to 2C states at high densities, and our measurements of the robustness of the $1/2$ FQHS against charge distribution asymmetry, suggest that the $1/2$ FQHS also makes a transition from 1C to 2C. Such a transition from a non-Abelian to Abelian state can open avenues for topological quantum information and quantum criticality.

We report an unconventional twofold-symmetric magnetoelastic coupling in Ni films, mediated by Rayleigh surface acoustic waves (SAWs). This unique magnetoelastic symmetry originates from a dominant vertical shear strain ${ϵ}_{yz}$, which becomes prominent due to the low effective elastic modulus of Ni film. As the film thickness increases, ${ϵ}_{yz}$ surpasses the conventional Rayleigh SAW strain ${ϵ}_{xx}$, a consequence originated from the elastic modulus mismatch at the film-substrate interface. This finding highlights the dominance of ${ϵ}_{yz}$ in soft thin film under SAW excitation, offering a new platform to excite strong nonreciprocal and topological magnon-phonon hybridization.

Driving materials using light with more than one frequency component is an emerging technique, enabled by advanced pulse-shaping capabilities in recent years. Here, we translate this technique to lattice vibrations by exciting multicolor phonons using terahertz cavities. In contrast to light, phonon frequencies are determined by the crystal structure and cannot readily be changed. We overcome this problem by tuning the frequencies of phonon polaritons in terahertz cavities to achieve the desired frequency ratios necessary for phononic Lissajous figures. This methodology enables dynamical crystallographic symmetry breaking and the creation of staggered phonon angular momentum and magnetic moment patterns.

We derive an exact master equation that captures the dynamics of a quadratic quantum system linearly coupled to a Gaussian environment of the same statistics: the Gaussian master equation (GME). Unlike previous approaches, our formulation applies universally to both bosonic and fermionic setups, and remains valid even in the presence of initial system-environment correlations, allowing for the exact computation of the system’s reduced density matrix across all parameter regimes. Remarkably, the GME shares the same operatorial structure as the Redfield equation and depends on a single kernel: a dressed environment correlation function accounting for all virtual interactions between the system and the environment. This simple structure grants a clear physical interpretation and makes the GME easy to simulate numerically, as we show by applying it to an open system based on two fermions coupled via superconductive pairing.

Kinetic equilibration at late times is physically required for heavy particles in a finite temperature medium. In Fokker-Planck dynamics, it is ensured by the Einstein relation between the drag and longitudinal momentum diffusion coefficients. However, in certain gauge field theories, this relation is violated at any nonzero heavy quark velocity. Recent work in strongly coupled $\mathcal{N}=4$ SYM gauge theory shows that the Kolmogorov equation for the heavy quark phase space distribution (that reduces to Fokker-Planck form upon truncating the momentum transfer probability distribution to second moments) does equilibrate even though the Fokker-Planck equation does not. Going beyond these (to date theory-specific) insights, we derive a universal equilibration condition for the kernel of the Kolmogorov equation and, consequently, for the momentum transfer probability distribution that holds in any quantum field theory with any coupling strength. This condition, which is the generalization of the Einstein relation to quantum field theories which feature non-Gaussian fluctuations, reveals that the asymmetry between energy loss and energy gain in the momentum transfer probability distribution takes a simple, theory-independent, form.

The D-measure of net-charge fluctuations quantifies the variance of net charge in strongly interacting matter. It was introduced over 20 years ago as a potential signal of quark-gluon plasma (QGP) in heavy-ion collisions, where it is expected to be suppressed due to the fractional electric charges of quarks. Measurements have been performed at RHIC and LHC, but the conclusion has been elusive in the absence of quantitative calculations for both scenarios. We address this issue by employing a recently developed formalism of density correlations and incorporate resonance decays, local charge conservation, and experimental kinematic cuts. We find that the hadron gas scenario is in fair agreement with the ALICE data for $\sqrt{s_{\mathrm{NN}}}=2.76\mathrm{TeV}$ Pb–Pb collisions only when a very short rapidity range of local charge conservation is enforced, while the QGP scenario is in excellent agreement with experimental data and largely insensitive to the range of local charge conservation. A Bayesian analysis of the data utilizing different priors yields moderate evidence for the freeze-out of charge fluctuations in the QGP phase relative to hadron gas. The upcoming high-fidelity measurements from LHC Run 2 will serve as a precision test of the two scenarios.

The electron density and electric field govern physical and chemical reactions in a secondary streamer discharge under atmospheric-pressure air. We present direct combinational measurements of these essential quantities and demonstrate their consistency by solving the continuity equation for electrons. The measurements enabled validity examination of previous computational studies and clarified contradictions; the prominence was a near-cathode phenomenon measured during primary-to-secondary transition, which caused unpredicted ionization inside the positive secondary discharge. The thorough comparison revealed that a fundamental governing mechanism to be established for the secondary discharge is current continuity.

We propose Josephson junction arrays as realistic platforms for observing nonequilibrium scaling laws characterizing the Kardar-Parisi-Zhang (KPZ) universality class, and space-time soliton proliferation. Focusing on a two-chain ladder geometry, we perform numerical simulations for the roughness function. Together with analytical arguments, our results predict KPZ scaling at intermediate time scales, extending over sufficiently long timescales to be observable, followed by a crossover to the asymptotic longtime regime governed by soliton proliferation.

We show that the Luttinger-Ward functional can be formulated as an operator insertion in the path integral and hence can be thought of as a generalized symmetry. The key result is that the associated charge, always quantized, defines the homotopy, not the physical charge. The disconnect between the two arises from divergences in the functional or, equivalently, zeros of the single-particle Green’s function. Such divergences produce an anomaly of the triangle-diagram type. As a result of this anomaly, we are able to account for the various deviations of the Luttinger count from the particle density. As a consequence, non-Fermi liquids can be classified generally by the well-known anomaly structures in particle physics. Charges descending from generalized symmetries, as in the divergence of the Luttinger-Ward functional, are inherently nonlocal, their key experimental signature.