Simulating large-scale lattice dynamics remains a long-standing challenge in condensed matter and materials science, where mechanical and thermal behaviors arise from coupled vibrational modes. We introduce a quantum algorithm that reformulates general harmonic lattice dynamics as a time-dependent Schrödinger equation governed by a sparse, Hermitian Hamiltonian. This enables the use of Hamiltonian simulation techniques on quantum devices, offering exponential speedup in the number of atoms $N$. Our approach applies to arbitrary harmonic lattices with vector-valued dynamics. A key ingredient is a matrix-valued Fejér-Riesz factorization of the phonon dynamical matrix, which preserves translational symmetry and enables efficient assembly of the Hamiltonian operator. We demonstrate the method’s applicability across a broad class of lattice models.

Establishing networks of quantum processors offers a path to scalable quantum computing and applications in communication and sensing. This requires first developing efficient interfaces between photons and multiqubit registers. In this Letter, we show how to entangle each individual matter qubit in a register of ten to a separate traveling photon. The qubits are encoded in a string of cotrapped atomic ions. By switching the trap confinement, ions are brought one at a time into the waist of an optical cavity and emit a photon via a laser-driven cavity-mediated Raman transition. The result is a train of photonic qubits, each near-maximally entangled by their polarization with a different ion qubit in the string. An average ion-photon Bell state fidelity of 92% is achieved, for an average probability for detecting each single photon of 9%. The technique is directly scalable to larger ion-qubit registers and opens up the near-term possibility of entangling distributed networks of trapped-ion quantum processors, sensing arrays, and clocks.

We study nonperturbative effects of torus partition function of the $T\overline{T}$-deformed 2D conformal field theory (CFT) by resurgence in this Letter and a companion paper. The deformed partition function can be written as an infinite series of the deformation parameter $\lambda$. We develop highly efficient methods to compute perturbative coefficients in the $\lambda$ expansion. To exemplify, the first 600 coefficients for the $T\overline{T}$-deformed free boson and free fermion are computed. The method can be generalized to any rational CFTs; we present the key idea in this Letter while relegating details and results to the companion paper. Equipped with the large order perturbative data, we provide convincing numerical evidence that the $\lambda$ series is asymptotic and not Borel resummable. We extract the nonperturbative contribution by resurgence and propose that they originate from new complex saddle points after analytically continuing the modular parameters in the integral representation of the partition function. The proposal is checked by comparing the predicted asymptotic behavior of the coefficients and large order perturbative data, which match nicely. The implications of these nonperturbative contributions for the Stokes phenomenon, which relates the positive and negative signs of $\lambda$, as well as possible comparisons with holography, is also discussed.

Hopfions—higher-dimensional topological quasiparticles with sophisticated 3D knotted spin textures discovered in condensed matter and photonic systems—show promise in high-density data storage and transfer. Here, we present crystalline structures of hopfions lying in space-time constructed by spatiotemporally structured light. Practical methodologies using bichromatic structured light beams or dipole arrays to assemble 1D and higher dimensional hopfion lattices are proposed, and a technique for tailoring topological orders is elucidated. Optical hopfion crystals constitute a new platform for high-dimensional topological information transfer.

Meniscus oscillations at interfaces between liquids, solids, and air significantly impact fluid dynamics and control. While idealized models exist, experimental data on capillary–gravity wave scattering involving meniscus effects remain limited. In this Letter, we systematically measured wave transmission past a surface-piercing barrier, focusing on meniscus effects. By varying the barrier’s surface properties and the wave frequencies, we explored how meniscus deformation influences wave transmission. The results are compared with simulations and limiting-case theories. We interpret that the meniscus water column formed beneath the barrier enhances flow coupling and increases wave transmission, while meniscus surface bending suppresses it by constraining motion. These competing effects explain the observed frequency and contact angle dependencies. Our findings provide insights into how meniscus dynamics govern surface wave behavior.

Mixing of the ablator material into the fuel of an inertial confinement fusion implosion reduces compression and enhances radiative losses, preventing ignition. We describe a novel use of charged-particle radiochemistry to measure the ablator mix in contact with the fusion hot spot. The capsule uses a graded Be-Cr layer to increase the confinement of the hot spot. ${}^{52}\mathrm{Mn}$ and ${}^{51}\mathrm{Cr}$ isotopes are collected from the implosion and counted, and the ratio is related to the amount of Cr mixed into the hot spot. Thus, a new diagnostic to determine the degradation due to mix on fusion implosions has been developed.

The multiplicity of orbitals in quantum systems significantly influences the competition between Kondo screening and local spin magnetization. The identification of orbital-specific processes is essential for advancing spintronic devices, as well as for enhancing the understanding of many-body quantum phenomena, but it remains a great challenge. Here, we use a combination of scanning tunneling microscopy/spectroscopy and electron spin resonance (ESR) spectroscopy to investigate single iron phthalocyanine (FePc) molecules on $\mathrm{MgO}/\mathrm{Ag}(100)$. We observe the coexistence of ESR and Kondo resonance from the Fe(II) ion center at a temperature well below the Kondo temperature $T_{\mathrm{K}}$, where the magnetic moments are determined to be 1 Bohr magneton ($1{\mu }_{\mathrm{B}}$), corresponding to a spin $S=1/2$ state in either of the ESR and Kondo resonance channels. On the basis of the observed in-plane twofold symmetry in the spatial distribution of ESR linewidths, in combination with density functional theory calculations, we attribute one spin $S=1/2$ state in the degeneracy-lifted $d_{\pi }$ orbital to the ESR channel, and the other in the highly screenable $d_{z^2}$ orbital to the Kondo resonance, respectively, within the framework of the $S=1$ two-channel Kondo model of an ordinary Fermi liquid.

We propose a scheme for retrieving the ultrafast valley polarization (VP) dynamics in two-dimensional hexagonal materials via attosecond circular dichroism (CD) transient absorption spectroscopy. This approach builds on the CD transition between the first and higher conduction bands induced by the circularly polarized probe pulses. The population imbalance at nonequivalent valleys in the first conduction band is proportionally mapped onto the difference in absorption coefficients of two probe pulses with opposite helicities, supporting an unprecedented quantitative retrieval of the corresponding VP dynamics with subfemtosecond time resolution. We theoretically demonstrate the scheme for $h$-BN and ${\mathrm{MoS}}_2$ through ab initio calculations, achieving an accurate retrieval of the VP dynamics, particularly the transient VP switching processes, with a time resolution of 250 as.

Models of how things spread often assume that transmission mechanisms are fixed over time. However, social contagions—the spread of ideas, beliefs, innovations—can lose or gain in momentum as they spread: ideas can get reinforced, beliefs strengthened, products refined. We study the impacts of such self-reinforcement mechanisms in cascade dynamics. We use different mathematical modeling techniques to capture the recursive, yet changing nature of the process. We find a critical regime with a range of power-law cascade size distributions with nonuniversal scaling exponents. This regime clashes with classic models, where criticality requires fine-tuning at a precise critical point. Self-reinforced cascades produce critical-like behavior over a wide range of parameters, which may help explain the ubiquity of power-law distributions in empirical social data.

We investigate nonreciprocal XY (NRXY) models defined on two-dimensional lattices in which the coupling strength of a spin with its neighbors varies with their position in the frame defined by the current spin orientation. As expected from the seminal work of Dadhichi et al., [Nonmutual torques and the unimportance of motility for long-range order in two-dimensional flocks, Phys. Rev. E 101, 052601 (2020)], we first show that nonreciprocity is akin to a self-propulsion: we derive a mean-field continuous theory identical to that of constant-density flocks. Like the latter, NRXY models exhibit a long-range ordered phase that is metastable to the nucleation of topological defects, and their asymptotic state is a dynamic foam of asters. We then show that in the metastable ordered phase, the lattice always induces anisotropy on large scales, pinning the direction of order and imposing a finite correlation length. Crucially, we demonstrate that this anisotropy is inescapable since, even when not explicitly present in the interaction rule, it is generated by fluctuations. In short, the ordered phase of lattice NRXY models is that of active clock models.

We present a detailed analytical and numerical examination, on square and triangular lattices, of the nonreciprocal planar spin model introduced in Dadhichi et al. [Phys. Rev. E 101, 052601 (2020)]. We show that the effect of lattice anisotropy should persist at large scales, leading to a “mass” for the angle field of the spins, and behavior not in the “Malthusian Toner-Tu” [Phys. Rev. Lett. 108, 088102 (2012)] universality class. Numerically, we find evidence of this mass at large values of our nonreciprocity parameter; for smaller values, we find power-law scaling of long-wavelength equal-time correlators in the polar-ordered phase of our lattice model over the system sizes and wave number range explored. Focussing on topological defects, we show numerically that defect interactions are highly anisotropic with respect to the mean ordering direction. In particular, the constituents of a $\pm 1$ pair are shielded from each other in a class of configurations, deferring their annihilation and allowing time for the nucleation of further defects. The result, we show numerically, is the destruction of the polarized phase via an aster apocalypse reminiscent of that found by Besse et al. [Phys. Rev. Lett. 129, 268003 (2022)] for flocks without number conservation.

At the extreme densities in neutron stars, a phase transition to deconfined quark matter is anticipated. Yet masses, radii, and tidal deformabilities offer only indirect measures of a first-order phase transition, requiring many detections to resolve or being ineffective observables if the discontinuity exists at lower densities. We report on a smoking-gun gravitational-wave signature of a first-order transition: the resonant tidal excitation of an interface mode. Using relativistic perturbation theory with an equation-of-state family informed by chiral effective field theory, we show that such a resonance may be detectable with next-generation interferometers and possibly already with LIGO $\mathrm{A}+$ for sufficiently loud events.

Single electrons confined to a free neon surface and manipulated through the circuit quantum electrodynamics architecture is a promising novel quantum computing platform. Understanding the exact physical nature of the electron-on-neon ($e\mathrm{Ne}$) charge states is important for realizing this platform’s potential for quantum technologies. We investigate how resonator trench depth and substrate surface properties influence the formation of $e\mathrm{Ne}$ charge states and their coupling to microwave resonators. Through experimental observation supported by modeling, we find that shallow-depth etching of the resonator features maximizes coupling strength. By comparing the trapping statistics and surface morphology of devices with altered trench roughness, our Letter reveals the role of fabrication-induced surface features in the formation of strongly coupled $e\mathrm{Ne}$ states.

The recent observational evidence of deviations from the Lambda cold dark matter model points toward the presence of evolving dark energy. The simplest possibility consists of a cosmological scalar field $\phi$, dubbed “quintessence,” driving the accelerated expansion. We assess the evidence for the existence of such a scalar field. We find that, if the accelerated expansion is driven by quintessence, the data favor a potential energy $V(\phi )$ that is concave, i.e., $m^2=d^{2}V/d{\phi }^2<0$. Furthermore, and more significantly, the data strongly favor a scalar field that is nonminimally coupled to gravity [Bayes factor $\log (B)=7.34\pm 0.6$], leading to time variations in the gravitational constant on cosmological scales, and the existence of fifth forces on smaller scales. The fact that we do not observe such fifth forces implies that either new physics must come into play on noncosmological scales or that quintessence is an unlikely explanation for the observed cosmic acceleration.

We investigate the inspiral of a high mass-ratio black hole binary located in the nucleus of a galaxy, where the primary central black hole is surrounded by a dense dark matter spike formed through accretion during the black hole growth phase. Within this spike, dark matter undergoes strong self-annihilation, producing a compact source of $\gamma$-ray radiation that is highly sensitive to spike density, while the binary emits gravitational waves at frequencies detectable by LISA. As the inspiraling binary interacts with the surrounding dark matter particles, it alters the density of the spike, thereby influencing the $\gamma$-ray flux from dark matter annihilation. We demonstrate that the spike self-annihilation luminosity decreases by 10% to 90% of its initial value, depending on the initial density profile and binary mass ratio, as the binary sweeps through the LISA band. This presents a new opportunity to indirectly probe dark matter through multimessenger observations of galactic nuclei.