Gravity-driven flows of granular matter are involved in a wide variety of situations, ranging from industrial processes to geophysical phenomena, such as avalanches or landslides. These flows are characterized by the coexistence of solid and fluid phases, whose stability is directly related to the erosion and sedimentation occurring at the solid-fluid interface. To describe these mechanisms, we build a microscopic model involving friction, geometry, and a nonlocal cooperativity emerging from the propagation of collisions. This new picture enables us to obtain a detailed description of the exchanges between the fluid and solid phases. The model predicts a phase diagram including the limits of erosion and sedimentation, in quantitative agreement with experiments and discrete-element-method simulations.

We study the decay rate $\theta (a)$ that characterizes the late time exponential decay of the first-passage probability density $F_a(t|0)\sim e^{-\theta (a)t}$ of a diffusing particle in a one dimensional confining potential $U(x)$, starting from the origin, to a position located at $a>0$. For general confining potential $U(x)$ we show that $\theta (a)$, a measure of the barrier (located at $a$) crossing rate, has three distinct behaviors as a function of $a$, depending on the tail of $U(x)$ as $x\to -\infty$. In particular, for potentials behaving as $U(x)\sim |x|$ when $x\to -\infty$, we show that a novel freezing transition occurs at a critical value $a=a_c$, i.e., $\theta (a)$ increases monotonically as $a$ decreases till $a_c$, and for $a\le a_c$ it freezes to $\theta (a)=\theta (a_c)$. Our results are established using a general mapping to a quantum problem and by exact solution in three representative cases, supported by numerical simulations. We show that the freezing transition occurs when in the associated quantum problem, the gap between the ground state (bound) and the continuum of scattering states vanishes.

Strong zero modes provide a paradigm for quantum many-body systems to encode local degrees of freedom that remain coherent far from the ground state. Example systems include ${\mathbb{Z}}_n$ chiral quantum clock models with strong zero modes related to ${\mathbb{Z}}_n$ parafermions. Here, we show how these models and their zero modes arise from geometric chirality in fermionic Mott insulators, focusing on $n=3$ where the Mott insulators are three-leg ladders. We link such ladders to ${\mathbb{Z}}_3$ chiral clock models by combining bosonization with general symmetry considerations. We also introduce a concrete lattice model which we show to map to the ${\mathbb{Z}}_3$ chiral clock model, perturbed by the Uimin-Lai-Sutherland Hamiltonian arising via superexchange. We demonstrate the presence of strong zero modes in this perturbed model by showing that correlators of clock operators at the edge remain close to their initial value for times exponentially long in the system size, even at infinite temperature.

We derive the fluctuation dynamics of a probe in weak coupling with a living medium, modeled as particles undergoing an active Ornstein-Uhlenbeck dynamics. Nondissipative corrections to the fluctuation-dissipation relation are written out explicitly in terms of time correlations in the active medium. A first term changes the inertial mass of the probe as a consequence of the persistence of the active medium. A second correction modifies the friction kernel. The resulting generalized Langevin equation benchmarks the motion induced on probes immersed in active versus passive media. The derivation uses nonequilibrium response theory.

Entangled resources enable quantum sensing that achieves Heisenberg scaling, a quadratic improvement on the standard quantum limit, but preparing large $N$ spin entangled states is challenging in the presence of decoherence. We present a quantum control strategy using highly nonlinear geometric phase gates which can be used for generic state or unitary synthesis on the Dicke subspace with $O(N)$ or $O(N^2)$ gates, respectively. The method uses a dispersive coupling of the spins to a common bosonic mode and does not require addressability, special detunings, or interactions between the spins. By using amplitude amplification our control sequence for preparing states ideal for metrology can be significantly simplified to $O(N^{5/4})$ geometric phase gates with action angles $O(1/N)$ that are more robust to mode decay. The geometrically closed path of the control operations ensures the gates are insensitive to the initial state of the mode and the sequence has built-in dynamical decoupling providing resilience to dephasing errors.

We report a search result for a light sterile neutrino oscillation with roughly 2200 live days of data in the RENO experiment. The search is performed by electron antineutrino (${\overline{\nu }}_e$) disappearance taking place between six 2.8 ${\mathrm{GW}}_{\mathrm{th}}$ reactors and two identical detectors located at 294 m (near) and 1383 m (far) from the center of the reactor array. A spectral comparison between near and far detectors can explore reactor ${\overline{\nu }}_e$ oscillations to a light sterile neutrino. An observed spectral difference is found to be consistent with that of the three-flavor oscillation model. This yields limits on ${\sin }^{2}2{\theta }_{14}$ in the ${10}^{-4}\lesssim |\mathrm{\Delta }{m}_{41}^2|\lesssim 0.5{\mathrm{eV}}^2$ region, free from reactor ${\overline{\nu }}_e$ flux and spectrum uncertainties. The RENO result provides the most stringent limits on sterile neutrino mixing at $|\mathrm{\Delta }{m}_{41}^2|\lesssim 0.002{\mathrm{eV}}^2$ using the ${\overline{\nu }}_e$ disappearance channel.

We present the first triaxial beyond-mean-field study of even-even super-heavy nuclei. Calculations for the even Flerovium isotopes towards the supposed $N=184$ neutron shell closure were performed using the effective finite-range density-dependent Gogny force. They include the restoration of the particle-number and angular-momentum symmetries and the mixing of different shapes using the generator coordinate method. The importance of the $\gamma$ degree of freedom is highlighted by comparing the triaxial to axial-symmetric calculations performed within the same framework. For the three even Fl isotopes between the prolate ${}^{288}\mathrm{Fl}$ and the oblate ${}^{296}\mathrm{Fl}$ triaxial ground-state shapes are predicted, whereas axial-symmetric calculations suggest a sharp prolate-oblate shape transition between ${}^{290}\mathrm{Fl}$ and ${}^{292}\mathrm{Fl}$. A novel type of shape coexistence, namely, that between two different triaxial shapes, is predicted to occur in ${}^{290}\mathrm{Fl}$. Finally, the existence of a neutron shell closure at $N=184$ is confirmed, while no evidence is found for $Z=114$ being a proton magic number.

Mass-separated ${{}^{187}\mathrm{Ta}}_{114}$ in a high-spin isomeric state has been produced for the first time by multinucleon transfer reactions, employing an argon gas-stopping cell and laser ionization. Internal $\gamma$ rays revealed a $T_{1/2}=7.3\pm 0.9\mathrm{s}$ isomer at $1778\pm 1\mathrm{keV}$, which decays through a rotational band with perturbations associated with the approach to a prolate-oblate shape transition. Model calculations show less influence from triaxiality compared to heavier elements in the same mass region. The isomer-decay reduced $E2$ hindrance factor $f_{\nu }=27\pm 1$ supports the interpretation that axial symmetry is approximately conserved.

Entangled photons produced by spontaneous parametric down-conversion have been of paramount importance for our current understanding of quantum mechanics and advances in quantum information. In this process, the quantum correlations of the down-converted photons are governed by the optical properties of the pump beam illuminating the nonlinear crystal. Extensively, the pump beam has been modeled by either coherent beams or by the well-known Gaussian–Schell model, which leads to the natural conclusion that a high degree of optical coherence is required for the generation of highly entangled states. Here, we show that when a novel class of partially coherent Gaussian pump beams is considered, a distinct type of quantum state can be generated for which the amount of entanglement increases inversely with the degree of coherence of the pump beam. This leads to highly incoherent yet highly entangled multiphoton states, which should have interesting consequences for photonic quantum information science.

Particles or waves scattered from a rotating black hole can be amplified through the process of Penrose superradiance, although this cannot currently be observed in an astrophysical setting. Here we theoretically show that analog Penrose superradiance arises naturally in the field of nonlinear optics. A loosely focused signal beam can experience gain or amplification as it glances off a strong vortex pump beam in a nonlinear defocusing medium. Amplification occurs only with the generation and trapping of negative norm modes in the core of the pump vortex, as predicted by Penrose. Our results elucidate a new regime of nonlinear optics involving the notion of an ergoregion, providing further insight into the processes and transient dynamics involved in Penrose superradiance.

We report the laser-induced solid-state transformation between a periodic “approximant” and quasicrystal in the Al-Cr system during rapid quenching. Dynamic transmission electron microscopy allows us to capture in situ the dendritic growth of the metastable quasicrystals. The formation of dendrites during solid-state transformation is a rare phenomenon, which we attribute to the structural similarity between the two intermetallics. Through ab initio molecular dynamics simulations, we identify the dominant structural motif to be a 13-atom icosahedral cluster transcending the phases of matter.

Two-particle spectroscopy with correlated electron pairs is used to establish the causal link between the secondary electron spectrum, the ($\pi +\sigma$) plasmon peak, and the unoccupied band structure of highly oriented pyrolytic graphite. The plasmon spectrum is resolved with respect to the involved interband transitions and clearly exhibits final state effects, in particular due to the energy gap between the interlayer resonances along the $\mathrm{\Gamma }A$ direction. The corresponding final state effects can also be identified in the secondary electron spectrum. Interpretation of the results is performed on the basis of density-functional theory and tight-binding calculations. Excitation of the plasmon perturbs the symmetry of the system and leads to hybridization of the interlayer resonances with atomlike ${\sigma }^{*}$ bands along the $\mathrm{\Gamma }A$ direction. These hybrid states have a high density of states as well as sufficient mobility along the graphite $c$ axis leading to the sharp $\sim 3\mathrm{eV}$ resonance in the spectrum of emitted secondary electrons reported throughout the literature.

The mobility edges (MEs) in energy that separate extended and localized states are a central concept in understanding the localization physics. In one-dimensional (1D) quasiperiodic systems, while MEs may exist for certain cases, the analytic results that allow for an exact understanding are rare. Here we uncover a class of exactly solvable 1D models with MEs in the spectra, where quasiperiodic on-site potentials are inlaid in the lattice with equally spaced sites. The analytical solutions provide the exact results not only for the MEs, but also for the localization and extended features of all states in the spectra, as derived through computing the Lyapunov exponents from Avila’s global theory and also numerically verified by calculating the fractal dimension. We further propose a novel scheme with experimental feasibility to realize our model based on an optical Raman lattice, which paves the way for experimental exploration of the predicted exact ME physics.

Fractional charge and statistics are hallmarks of low-dimensional interacting systems such as fractional quantum Hall (QH) systems. Integer QH systems are regarded as noninteracting, yet they can have fractional charge excitations when they couple to another interacting system or time-dependent voltages. Here, we notice Abelian fractional mutual statistics between such a fractional excitation and an electron, and propose a setup for detection of the statistics in which a fractional excitation is generated at a source and injected to a Mach-Zehnder interferometer (MZI) in the integer QH regime. In a parameter regime, the dominant interference process involves braiding, via double exchange, between an electron excited at an MZI beam splitter and the fractional excitation. The braiding results in the interference phase shift by the phase angle of the mutual statistics. This proposal for directly observing the fractional mutual statistics is within experimental reach.

Atomic force microscopy experiments found that GB1, a typical two-state model protein used for study of folding and unfolding dynamics, can sustain forces of more than 100 pN, but its response to low forces still remains unclear. Using ultrastable magnetic tweezers, we discovered that GB1 has an unexpected nonmonotonic force-dependent unfolding rate at 5–160 pN, from which a free energy landscape with two main barriers and a hidden intermediate state was constructed. A model combining two separate models by Dudko et al. with two pathways between the native state and this intermediate state is proposed to rebuild the unfolding dynamics over the full experimental force range. One candidate of this transient intermediate state is the theoretically proposed molten globule state with a loosely collapsed conformation, which might exist universally in the folding and unfolding processes of two-state proteins.

We perform a sequence of binary black hole simulations with increasingly small mass ratios, reaching to a $128:1$ binary that displays 13 orbits before merger. Based on a detailed convergence study of the $q=m_1/m_2=1/15$ nonspinning case, we apply additional mesh refinement levels around the smaller hole horizon [30] to reach successively the $q=1/32$, $q=1/64$, and $q=1/128$ cases. Roughly a linear computational resources scaling with $1/q$ is observed on eight-nodes simulations. We compute the remnant properties of the merger: final mass, spin, and recoil velocity, finding precise consistency between horizon and radiation measures. We also compute the gravitational waveforms: their peak frequency, amplitude, and luminosity. We compare those values with predictions of the corresponding phenomenological formulas, reproducing the particle limit within 2%, and we then use the new results to improve their fitting coefficients.

The rapidity anomalous dimension (RAD), or Collins-Soper kernel, defines the scaling properties of transverse momentum dependent distributions and can be extracted from the experimental data. I derive a self-contained nonperturbative definition that represents RAD without reference to a particular process. This definition makes possible exploration of the properties of RAD by theoretical methods on one side, and the properties of QCD vacuum with collider measurements on another side. To demonstrate these possibilities, I compute the power correction to RAD, its large-$b$ asymptotic, and compare these estimations with recent phenomenological extractions.

We show that the correlation between the elliptic momentum anisotropy $v_2$ and the average transverse momentum $[p_T]$ at fixed multiplicity in small system nuclear collisions carries information on the origin of the observed momentum anisotropy. A calculation using a hybrid IP-Glasma+music+UrQMD model that includes contributions from final state response to the initial geometry as well as initial state momentum anisotropies of the color glass condensate predicts a characteristic sign change of the correlator $\widehat{\rho }(v_2^2,[p_T])$ as a function of charged particle multiplicity in $p+\text{Au}$ and $d+\text{Au}$ collisions at $\sqrt{s}=200\mathrm{GeV}$, and $p+\mathrm{Pb}$ collisions at $\sqrt{s}=5.02\mathrm{TeV}$. This sign change is absent in calculations without initial state momentum anisotropies. The model further predicts a qualitative difference between the centrality dependence of $\widehat{\rho }(v_2^2,[p_T])$ in $\mathrm{Au}+\mathrm{Au}$ collisions at $\sqrt{s}=200\mathrm{GeV}$ and $\mathrm{Pb}+\mathrm{Pb}$ collisions at $\sqrt{s}=5.02\mathrm{TeV}$, with only the latter showing a sign change in peripheral events. Predictions for $\mathrm{O}+\mathrm{O}$ collisions at different collision energy show a similar behavior. Experimental observation of these distinct qualitative features of $\widehat{\rho }(v_2^2,[p_T])$ in small and large systems would constitute strong evidence for the presence and importance of initial state momentum anisotropies predicted by the color glass condensate effective theory.