Temporal metamaterials, created by modulating the refractive index in time, offer powerful means of controlling wave propagation but still lack a systematic design methodology. Here, we develop an analytic inverse-design framework rooted in space-time duality and the established theory of one-dimensional spatial inverse scattering. By prescribing reflection (backward-wave) and transmission (forward-wave) responses in rational-function form, we obtain closed-form refractive-index modulations that are guaranteed to be physically admissible. This approach avoids iterative optimization and provides direct analytic control of the modulation. We illustrate the method with syntheses of mathematical operators, such as derivatives and integrals, as well as Chebyshev- and Butterworth-type filters, and validate the results through finite-difference time-domain simulations. Our findings establish a general route to temporal media with tailored functional and spectral responses, enabling applications in wave-based information processing, programmable filtering, and amplification schemes inspired by photonic time crystals.

It has been a long, interesting, and mysterious nonequilibrium phenomenon that hot water may freeze faster than warm water, which is known as Mpemba effect. Studying its physical origin and exploring new Mpembalike effects have attracted broad interests. Here, we report experimental evidence of a novel Mpembalike effect in the aging process of glasses: a glass with an initial higher energy state ages (enthalpy decreases) faster and surpasses the glass with an initial lower energy state. This phenomenon is universally observed in different types of structural glasses, including metallic, polymer, and molecular glasses. The underlying thermodynamic mechanism is also studied using high-precision nanocalorimetry. It is found that preannealing at a higher temperature is critical to triggering the faster aging kinetics of the Mpembalike effect. This is attributed to the activation of a secondary $\beta$ relaxation peak with a substantially lower kinetic barrier than the primary $\alpha$ relaxation peak. Thus, besides the $\alpha$ relaxation, the $\beta$ relaxation plays a pivotal role in the enthalpy aging process, which is very sensitive to the thermal history. These findings may have broad implications for optimizing the thermal treatment and relaxations of different types of glasses.

We present an approach for efficiently simulating strongly damped quantum systems subjected to periodic driving, employing a periodic matrix product operator representation of the influence functional. This representation enables the construction of a numerically exact Floquet propagator that captures the non-Markovian open system dynamics, thus providing a dissipative analog to the Floquet Hamiltonian of driven isolated quantum systems. We apply this method to study the asymptotic heating of a reservoir in spin-boson models, characterizing the deviation from equilibrium conditions. Moreover, we show how a local driving of two qubits can be utilized to stabilize a transient entanglement buildup of the qubits originating from the interaction with a common environment. Our results make it possible to directly study both stationary and transient dynamics of strongly damped and driven quantum systems within a transparent theoretical and numerical framework.

Quantum simulation is widely regarded as one of the most promising applications of quantum computing. A critical challenge in this domain is understanding and quantifying the accumulation of algorithmic errors over time, which is essential for designing more efficient simulation algorithms and for assessing the resources required to achieve quantum advantage. Conventional error analyses typically rely on the triangle inequality to bound the total simulation error, but such approaches tend to overestimate errors by ignoring error interference—a phenomenon in which errors from different simulation segments partially cancel. Here, we introduce a new framework for directly estimating long-time algorithmic errors in segmented quantum simulations. Our approach captures the full structure of error interference, enabling significantly tighter and more accurate error bounds. We identify both necessary and sufficient conditions for strict error interference and propose the notion of approximate error interference to account for realistic, imperfect cancellation. We demonstrate the broad applicability of our framework across a range of models and settings, including Heisenberg and Fermi-Hubbard systems, lattice Hamiltonians with power-law interactions, higher-order Trotter decompositions, and adiabatic evolution. By providing a unified and practical methodology for analyzing error interference, our Letter advances the theoretical understanding of quantum simulation and informs the design and benchmarking of algorithms for near-term and future quantum hardware.

We experimentally optimize the frequency of flux-tunable couplers in a superconducting quantum processor to minimize the impact of spectator transmons during quantum operations (single-qubit gates, two-qubit gates, and readout) on other transmons. We adapt a popular transmonlike tunable-coupling element, achieving high-fidelity, low-leakage controlled-$Z$ gates with unipolar, fast-adiabatic pulsing only on the coupler. We demonstrate the ability of the tunable coupler to null residual-$ZZ$ coupling as well as exchange couplings in the one- and two-excitation manifolds. However, the nulling of these coherent interactions is not simultaneous, prompting the exploration of trade-offs. We present experiments pinpointing spectator effects on specific quantum operations. We also study the combined effect on the three types of operations using repeated quantum parity measurements.

We discuss a modification of a recently developed numerical scheme for evolving spherically symmetric self-gravitating systems to include the effects of self-interacting dark matter. The approach is far more efficient than traditional $N$-body simulations and cross sections with different dependencies on velocity and scattering angle are easily accommodated. To demonstrate, we provide results of a simulation, which runs quickly on a personal computer, that shows the expected initial flattening of the inner region of a Navarro-Frenk-White (NFW) halo as well as the later gravothermal collapse instability that leads to a dense core at the galactic center. We note that this approach can also be used, with some augmentation, to simulate the dynamics in globular clusters by modeling gravitational hard scattering as a self-interaction.

We present a quantitative demonstration that, without additional theoretical and experimental efforts, realistic variations in final-state interaction (FSI) modeling may alter reconstructed neutrino-energy spectra at next-generation long-baseline experiments by amounts comparable to, or larger than, variations induced by oscillation-parameter shifts at their projected precision. Using the DUNE flux and baseline as a case study, we show that these FSI-driven distortions can mimic the effects of changes in the oscillation parameters $\mathrm{\Delta }{m}_{32}^2$ or ${\delta }_{CP}$, producing a potential degeneracy. Our analysis thereby underscores the urgent need for an improved characterization of FSI to enable robust constraints from near detectors through the development of theory-driven uncertainty parameterizations benchmarked with dedicated new measurements.

A search for $CP$ violation with an entangled system of ${\mathrm{\Xi }}^{-}{\overline{\mathrm{\Xi }}}^{+}$ pairs is performed, using $(10,087\pm 44)\times {10}^{6}J/\psi$ events collected with the BESIII experiment. A nine-dimensional helicity amplitude is used to fit $e^{+}{e}^{-}\to J/\psi \to {\mathrm{\Xi }}^{-}{\overline{\mathrm{\Xi }}}^{+}$ and its subsequent decays. The ${\mathrm{\Xi }}^{-}$ and ${\overline{\mathrm{\Xi }}}^{+}$ decay parameters are determined with higher precision compared to the best results reported so far. Furthermore, the strong phase difference, $({\delta }_P-{\delta }_S)=(0.3\pm 1.2\pm 0.2)\times {10}^{-2}\mathrm{rad}$, and the weak phase difference, $({\xi }_P-{\xi }_S)=(-0.2\pm 1.2\pm 0.1)\times {10}^{-2}\mathrm{rad}$, are directly determined. These are the most precise measurements to date. The $CP$ asymmetry observables $A_{CP}^{\mathrm{\Xi }}=(-7.8\pm 4.8\pm 0.8)\times {10}^{-3}$ and $\mathrm{\Delta }{\varphi }_{CP}^{\mathrm{\Xi }}=(0.6\pm 5.1\pm 0.2)\times {10}^{-3}\mathrm{rad}$ are determined, which are consistent with $CP$ conservation. In addition, independent measurements of the $\mathrm{\Lambda }$ decay parameter and $CP$ asymmetry $A_{CP}^{\mathrm{\Lambda }}=(-2.9\pm 4.3\pm 0.7)\times {10}^{-3}$ are also obtained, which are in agreement with the previous measurements, but with much improved precision.

Experiments using intermediate- to high-energy radioactive nuclear beams present numerous findings. Extracting important properties of physical observables relies on a firm theoretical analysis. Though Glauber theory is believed to work well, no convincing calculation has so far been done. We perform Glauber-theory calculations of both elastic differential cross sections and total reaction cross sections for $p+{}^{12}\mathrm{C}$, ${}^{12}\mathrm{C}+{}^{12}\mathrm{C}$, and ${}^6\mathrm{He}+{}^{12}\mathrm{C}$ systems. The wave functions of both ${}^6\mathrm{He}$ and ${}^{12}\mathrm{C}$ are generated by variational Monte Carlo calculations with spatial and spin-isospin correlations induced by realistic two- and three-nucleon potentials. Glauber’s phase-shift function is computed by Monte Carlo integration up to all orders of nucleon-nucleon multiple scatterings. We show an excellent performance of the Glauber description to the selected data on the above systems. We also find that the cumulant expansion of the phase-shift function converges rapidly up to the second order for the above systems. This finding will open up interesting applications for the analysis of high-energy nuclear experiments.

We demonstrate that coupling itinerant electrons to a noncollinear classical exchange field can induce anisotropic Josephson coupling between superconducting $d$ vectors, analogous to the Dzyaloshinskii-Moriya and $\mathrm{\Gamma }$-type interactions in magnetism. Using perturbative methods, we analyze an $s\text{−}d$ model on a geometrically frustrated lattice. Noncollinear local spin textures generate spin triplet pairing correlations and can favor spatially varying superconducting order due to anisotropic Josephson couplings between $d$ vectors, endowing a “pliability” to the pairing order that competes with the superfluid stiffness. For nonunitary pairing, this spatial texture of $d$ vectors can give rise to anomalous vortices in the absence of an external magnetic field. We further predict a Josephson diode effect with efficiency proportional to the spin chirality of the underlying magnetic texture. These results establish a link between frustrated magnetism and spatial textures of triplet superconducting pairing, with implications for a range of materials such as ${\mathrm{Mn}}_3\mathrm{Ge}$ and $4H_b\text{−}{\text{TaS}}_2$, where superconductivity can be proximity induced or intrinsic.

Understanding the $g$-factor physics of Si/SiGe quantum dots is crucial for realizing high-quality spin qubits. While previous work has explained some aspects of $g$-factor physics in idealized geometries, the results do not extend to general cases and they miss several important features. Here, we construct a theory that gives $g$ in terms of readily computable matrix elements, and can be applied to all Si/SiGe heterostructures of current interest. As a concrete example, which currently has no $g$-factor understanding, we study the so-called wiggle well structure, containing Ge concentration oscillations inside the quantum well. Here we find a significant renormalization of the $g$ factor compared to conventional Si/SiGe quantum wells. We also uncover a giant $g$-factor suppression of order $\mathcal{O}(1)$, which arises due to spin-valley coupling, and occurs at locations of low valley splitting. Our work therefore opens up new avenues for $g$-factor engineering in Si/SiGe quantum dots.

We demonstrate that anisotropic magnetoresistance (AMR) in metal-ferromagnet bilayers can arise entirely from interfacial scattering, without invoking bulk spin Hall or inverse spin Hall effects. Using a minimal boundary-value formulation of the Boltzmann equation with interfacial exchange and Rashba spin-orbit coupling, we identify a resonant spin-filtering mechanism whereby one spin projection becomes immune to backscattering at a clean interface. This mechanism quantitatively reproduces the magnitude ($\mathrm{\Delta }\rho /\rho \sim {10}^{-4}–{10}^{-3}$), thickness dependence, and angular symmetry conventionally attributed to spin Hall magnetoresistance in $\mathrm{Pt}/\mathrm{YIG}$. Crucially, the maximal AMR scales linearly in the smaller of the interfacial exchange or spin-orbit coupling: a parametric behavior forbidden in any spin-Hall-based theory. The effect is intrinsically sensitive to interface quality, charge transfer, and disorder, providing clear signatures that can be experimentally tested. Our results establish interfacial spin filtering as an essential and previously overlooked origin of AMR in metal-ferromagnet heterostructures, calling for a fundamental reassessment of magnetotransport mechanisms in spin-orbit-coupled metals.

Parametric instabilities are a known feature of periodically driven dynamic systems; at particular frequencies and amplitudes of the driving modulation, the system’s quasiperiodic response undergoes a frequency lock-in, leading to a periodically unstable response. Here, we demonstrate an analogous phenomenon in a purely static context. We show that the buckling patterns of an elastic beam resting on a modulated Winkler foundation display the same kind of frequency lock-in observed in dynamic systems. Through simulations and experiments, we reveal that compressed elastic strips with modulated height alternate between predictable quasiperiodic and periodic buckling modes. Our findings uncover previously unexplored analogies between structural and dynamic instabilities, highlighting how even simple elastic structures can give rise to rich and intriguing behaviors.

Chaotic quantum systems at finite entropy density are expected to act as their own heat baths, rapidly dephasing local quantum superpositions. We argue that in fact this dephasing is generically subexponential in one-dimensional systems with conservation laws: all local correlation functions decay as $\exp [-\mathcal{O}(t^{\alpha })]$ with $0\le \alpha \le 2/3$, even when the operators are orthogonal to all hydrodynamic modes. The mechanism is diffusion-limited dephasing, in which rare low-entropy regions (“voids”) protect quantum coherences. This intrinsically quantum effect lies beyond standard hydrodynamics and disappears under extrinsic dephasing. In random charge-conserving circuits we find $\alpha =1/2$, while in generic translation-invariant Floquet systems we bound $\alpha \le 2/3$. Our arguments are general, subject principally to the assumption that thermal fluctuations can create regions of zero entropy density. In systems with energy conservation, this assumption is automatically satisfied because of the third law of thermodynamics.