Some gauge theories with a spontaneously broken $U(1)$ symmetry exhibit fractional Aharonov-Bohm (AB) phases around vortices in the Higgs regime. We discuss continuity between confining and Higgs regimes in such gauge theories with fundamental matter fields, focusing on the AB phases. By explicit calculations in relevant lattice models, we demonstrate that the AB phase is smoothly connected between the confining and Higgs regimes, supporting the Higgs-confinement continuity. This result provides new insight into phase structures of gauge theories with superfluidity, such as dense QCD.

A general organizing principle is proposed that can be used to derive the equations of motion describing the near-equilibrium dynamics of causal and thermodynamically stable relativistic systems. The latter are found to display some new type of universal behavior near equilibrium that allows them to be grouped into universality classes defined by their degrees of freedom, information content, and conservation laws. The universality classes expose a number of surprising equivalences between different theories, shedding new light on the near-equilibrium behavior of relativistic systems.

$K^{+}{K}^{-}$ pairs may be produced in photonuclear collisions, either from the decays of photoproduced $\varphi (1020)$ mesons or directly as nonresonant $K^{+}{K}^{-}$ pairs. Measurements of $K^{+}{K}^{-}$ photoproduction probe the couplings between the $\varphi (1020)$ and charged kaons with photons and nuclear targets. The kaon-proton scattering occurs at energies far above those available elsewhere. We present the first measurement of coherent photoproduction of $K^{+}{K}^{-}$ pairs on lead ions in ultraperipheral collisions using the ALICE detector, including the first investigation of direct $K^{+}{K}^{-}$ production. There is significant $K^{+}{K}^{-}$ production at low transverse momentum, consistent with coherent photoproduction on lead targets. In the mass range $1.1<M_{KK}<1.4\mathrm{GeV}/c^2$ above the $\varphi (1020)$ resonance, for rapidity $|y_{KK}|<0.8$ and $p_{T,KK}<0.1\mathrm{GeV}/c$, the measured coherent photoproduction cross section is $\mathrm{d}\sigma /\mathrm{d}y=3.37\pm 0.61(\text{stat})\pm 0.15(\mathrm{syst})\mathrm{mb}$. The center-of-mass energy per nucleon of the photon-nucleus (Pb) system $W_{\gamma \mathrm{Pb},n}$ ranges from 33 to 188 GeV, far higher than previous measurements on heavy-nucleus targets. The cross section is larger than expected for $\varphi (1020)$ photoproduction alone. The mass spectrum is fit to a cocktail consisting of $\varphi (1020)$ decays, direct $K^{+}{K}^{-}$ photoproduction, and interference between the two. The confidence regions for the amplitude and relative phase angle for direct $K^{+}{K}^{-}$ photoproduction are presented.

We report on an experimental observation of the streaking of betatron x rays in a curved laser wakefield accelerator. The streaking of the betatron x rays was realized by launching a laser pulse into a plasma with a transverse density gradient. By controlling the plasma density and the density gradient, we realized the steering of the laser driver, electron beam, and betatron x rays simultaneously. Moreover, we observed an energy-angle correlation of the streaked betatron x rays and utilized it in diagnosing the electron acceleration process in a single-shot mode. Our work could also find applications in advanced control of laser beam and particle propagation. More importantly, the angular streaked betatron x ray has an intrinsic spatiotemporal correlation, which makes it a promising tool for single-shot pump-probe applications.

When a spin-splitting field is introduced to a thin film superconductor, the spin currents polarized along the field couples to energy currents that can only decay via inelastic scattering. We study spin and energy injection into such a superconductor where spin-orbit impurity scattering yields inverse spin-Hall and spin-swapping currents. We show that the combined presence of a spin-splitting field, superconductivity, and inelastic scattering gives rise to a strong enhancement of the ordinary inverse spin-Hall effect, as well as unique inverse spin-Hall and spin-swapping signals orders of magnitude stronger than the ordinary inverse spin-Hall signal. These can be completely controlled by the orientation of the spin-splitting field, resulting in a long-range charge and spin accumulations detectable much further from the injector than in the normal state. While the enhanced inverse spin-Hall signals offer a major improvement in spin detection sensitivity, the unique spin-swap signals can be utilized for designing devices where both the spin and current directions are controlled and altered throughout the geometry.

The nature of the anomalous metal state has been a major puzzle in condensed matter physics for more than three decades. Here, we report systematic investigation and modulation of the anomalous metal states in high-temperature interface superconductor FeSe films on ${\mathrm{SrTiO}}_3$ substrate. Remarkably, under zero magnetic field, the anomalous metal state persists up to 20 K in pristine FeSe films, an exceptionally high temperature standing out from previous observations. In stark contrast, for the FeSe films with nanohole arrays, the characteristic temperature of the anomalous metal state is considerably reduced. We demonstrate that the observed anomalous metal states originate from the quantum tunneling of vortices adjusted by the Ohmic dissipation. Our work offers a perspective for understanding the origin and modulation of the anomalous metal states in two-dimensional bosonic systems.

Linear elastic fracture mechanics theory predicts that the speed of crack growth is limited by the Rayleigh wave speed. Although many experimental observations and numerical simulations have supported this prediction, some exceptions have raised questions about its validity. The underlying reasons for these discrepancies and the precise limiting speed of dynamic cracks remain unknown. Here, we demonstrate that tensile (mode I) cracks can exceed the Rayleigh wave speed and propagate at supershear speeds. We show that taking into account geometric nonlinearities, inherent in most materials, is sufficient to enable such propagation modes. These geometric nonlinearities modify the crack-tip singularity, resulting in different crack-tip opening displacements, cohesive zone behavior, and energy flows towards the crack tip.

Orbital currents and accumulation provide a new avenue to boost spintronic effects in nanodevices. Here, we use interconversion effects between charge current and orbital angular momentum to demonstrate a dramatic increase in the magnon spin injection and detection efficiencies in nanodevices consisting of a magnetic insulator contacted by $\mathrm{Pt}/{\mathrm{CuO}}_{\mathrm{x}}$ electrodes. Moreover, we note distinct variations in efficiency for magnon spin injection and detection, indicating a disparity in the direct and inverse orbital Rashba-Edelstein effect efficiencies.

Hedgehog and antihedgehog spin textures in magnets behave as emergent monopoles and antimonopoles, which give rise to astonishing transport and electromagnetic phenomena. Using the Kondo-lattice model in three dimensions, we theoretically study collective spin-wave excitation modes of magnetic hedgehog lattices which have recently been discovered in itinerant magnets such as ${\mathrm{MnSi}}_{1-x}{\mathrm{Ge}}_x$ and ${\mathrm{SrFeO}}_3$. It is revealed that the spin-wave modes, which appear in the subterahertz regime, have dominant amplitudes localized at Dirac strings connecting hedgehog-antihedgehog pairs and are characterized by their translational oscillations. It is found that their spectral features sensitively depend on the number and configuration of the Dirac strings and, thus, can be exploited for identifying the topological phase transitions associated with the monopole-antimonopole pair annihilations.

The utilization of Josephson vortices as information carriers in superconducting digital electronics is hindered by the lack of reliable displacement and localization mechanisms. In this Letter, we experimentally investigate planar Nb junctions with an intrinsic phase shift and nonreciprocity induced by trapped Abrikosov vortices. We demonstrate that the entrance of a single Josephson vortex into such junctions triggers the switching between metastable $\pm \pi$ semifluxon states. We showcase controllable manipulation between these states using short current pulses and achieve a nondestructive readout by a nearby junction. Our observations pave the way toward ultrafast and energy-efficient digital Josephson electronics.

During electrochemical signal transmission through synapses, triggered by an action potential (AP), a stochastic number of synaptic vesicles (SVs), called the “quantal content,” release neurotransmitters in the synaptic cleft. It is widely accepted that the quantal content probability distribution is a binomial based on the number of ready-release SVs in the presynaptic terminal. But the latter number itself fluctuates due to its stochastic replenishment, hence the actual distribution of quantal content is unknown. We show that exact distribution of quantal content can be derived for general stochastic AP inputs in the steady state. For fixed interval AP train, we prove that the distribution is a binomial, and corroborate our predictions by comparison with electrophysiological recordings from MNTB-LSO synapses of juvenile mice. For a Poisson train, we show that the distribution is nonbinomial. Moreover, we find exact moments of the quantal content in the Poisson and other general cases, which may be used to obtain the model parameters from experiments.

Living systems are maintained out of equilibrium by external driving forces. At stationarity, they exhibit emergent selection phenomena that break equilibrium symmetries and originate from the expansion of the accessible chemical space due to nonequilibrium conditions. Here, we use the matrix-tree theorem to derive upper and lower thermodynamic bounds on these symmetry-breaking features in linear and catalytic biochemical systems. Our bounds are independent of the kinetics and hold for both closed and open reaction networks. We also extend our results to master equations in the chemical space. Using our framework, we recover the thermodynamic constraints in kinetic proofreading. Finally, we show that the contrast of reaction-diffusion patterns can be bounded only by the nonequilibrium driving force. Our results provide a general framework for understanding the role of nonequilibrium conditions in shaping the steady-state properties of biochemical systems.

We develop a framework for characterizing quantum temporal correlations in a general temporal scenario, in which an initial quantum state is measured, sent through a quantum channel, and finally measured again. This framework does not make any assumptions on the system nor on the measurements, namely, it is device independent. It is versatile enough, however, to allow for the addition of further constraints in a semi-device-independent setting. Our framework serves as a natural tool for quantum certification in a temporal scenario when the quantum devices involved are uncharacterized or partially characterized. It can hence also be used for characterizing quantum temporal correlations when one assumes an additional constraint of no-signalling in time, there are upper bounds on the involved systems’ dimensions, rank constraints—for which we prove genuine quantum separations over local hidden variable models—or further linear constraints. We present a number of applications, including bounding the maximal violation of temporal Bell inequalities, quantifying temporal steerability, and bounding the maximum successful probability in quantum randomness access codes.

An effective time-dependent Hamiltonian can be implemented by making a quantum system fly through an inhomogeneous potential, realizing, for example, a quantum gate on its internal degrees of freedom. However, flying systems have a spatial spread that will generically entangle the internal and spatial degrees of freedom, leading to decoherence in the internal state dynamics, even in the absence of any external reservoir. We provide formulas valid at all times for the dynamics, fidelity, and change of entropy for ballistic particles with small spatial spreads, quantified by $\mathrm{\Delta }x$. This non-Markovian decoherence can be significant for ballistic flying qubits (scaling as $\mathrm{\Delta }{x}^2$) but usually not for flying qubits carried by a moving potential well (scaling as $\mathrm{\Delta }{x}^6$). We also discuss a method to completely counteract this decoherence for a ballistic qubit later measured.

We argue that there is a lower bound of order ${10}^{-19}\mathrm{eV}$ on dark matter mass if it is produced after inflation via a process with finite correlation length. We rely on nondetection of free-streaming suppression and white-noise enhancement of density perturbations as the observational inputs.

Higgsinos with masses near the electroweak scale can solve the hierarchy problem and provide a dark matter candidate, while detecting them at the LHC remains challenging if their mass splitting is $\mathcal{O}(1\mathrm{GeV})$. This Letter presents a novel search for nearly mass-degenerate Higgsinos in events with an energetic jet, missing transverse momentum, and a low-momentum track with a significant transverse impact parameter using $140{\mathrm{fb}}^{-1}$ of proton-proton collision data at $\sqrt{s}=13\mathrm{TeV}$ collected by the ATLAS experiment. For the first time since LEP, a range of mass splittings between the lightest charged and neutral Higgsinos from 0.3 to 0.9 GeV is excluded at 95% confidence level, with a maximum reach of approximately 170 GeV in the Higgsino mass.

Symmetry-breaking phase transitions are central to our understanding of states of matter. When a continuous symmetry is spontaneously broken, new excitations appear that are tied to fluctuations of the order parameter. In superconductors and fermionic superfluids, the phase and amplitude can fluctuate independently, giving rise to two distinct collective branches. However, amplitude fluctuations are difficult to both generate and measure, as they do not couple directly to the density of fermions and have only been observed indirectly to date. Here, we excite amplitude oscillations in an atomic Fermi gas with resonant interactions by an interaction quench. Exploiting the sensitivity of Bragg spectroscopy to the amplitude of the order parameter, we measure the time-resolved response of the atom cloud, directly revealing amplitude oscillations at twice the frequency of the gap. The magnitude of the oscillatory response shows a strong temperature dependence, and the oscillations appear to decay faster than predicted by time-dependent Bardeen-Cooper-Schrieffer theory applied to our experimental setup.