Spin-and-valley-tronics explores the spin and valley degree of freedom for power-efficient and high-speed information storage and processing. A critical challenge in advancing spin-and-valley-tronic devices toward quantum operation lies in achieving coherent control over the spin and valley dynamics. A gigantic magnetic field is generally required to initiate fast coherent spin and valley precession to beat the subpicosecond valley decoherence in transition metal dichalcogenides. The magnetic proximity effect (MPE) can enhance the effective valley and spin magnetic moment, which has been explored extensively for engineering the magneto-optical properties of magnetic heterostructure. However, its influence on ultrafast coherent spin and valley dynamics remains unexplored. Herein, we investigate the MPE in ${\mathrm{WSe}}_2/\mathrm{CrSBr}$ heterostructures, which feature resonantly aligned band structures that promote strong charge transfer (CT) with a noncollinear spin configuration. The valley Zeeman splitting and emission helicity of ${\mathrm{WSe}}_2/\mathrm{CrSBr}$ are found substantially enhanced. We show that the enhanced exchange coupling together with noncollinear CT spin state drives subpicosecond coherent spin and valley precession, giving rise to anomalous magneto-optical properties. The anomalous MPE also leads to the observation of switchable exchange bias on the 2D ferromagnet with light helicity. Our work sheds light on the intriguing coherent spin and valley dynamics at the magnetic van der Waals interface and paves the way for ultrafast encoding and processing of coherent spin and valley information.

We study the spin-$1/2$ Kitaev honeycomb gapless spin liquid in the presence of Stone-Wales-type local lattice defects with odd-sided plaquettes. While the clean Kitaev model has no finite-temperature phase transitions, we find that introducing a finite defect density $n_d\approx {10}^{-4}–{10}^{-2}$ produces a true phase transition with a sizeable $T_c\approx 2n_d$ in units of the Kitaev exchange. The resulting non-Abelian chiral quantum spin liquid exhibits scalar spin chirality and electron orbital magnetization which peak near lattice defects. This disorder-driven instability relies on an emergent long range ferromagnetic interaction $r^{-\gamma }$ ($\gamma \approx 2.7$) between defect chiralities, mediated by the nearly gapless fermions, with implications for topology generation in Dirac cones with fluctuating mass terms.

Understanding the nonlocality of multipartite quantum systems provides valuable insights into their behaviors and potential applications. In this Letter, assuming a quantum network inflated with multiple copies of genuine multipartite entangled states, we propose a novel noise-robust approach to test the genuine multipartite nonlocality inherent in each copy under Svetlichny’s biseparable model. This extends Gisin’s theorem to an arbitrary number of parties, establishing the equivalence among genuine multipartite nonlocality, genuine multipartite steering, and genuine multipartite entanglement for all multipartite pure states under the multiple copies assumption. In the experiment, we employ a hybrid photonic quantum network to verify the genuine tripartite nonlocality of generalized Greenberger-Horne-Zeilinger and W states beyond previously explored parameter regimes. This Letter not only offers a unified robust method on exploring multipartite quantum correlations, but also opens a new avenue for studying genuine multipartite nonlocality through network-distributed multicopy quantum states and different network topologies.

We present a novel method for extracting the energy spectrum of ultracold neutrons from magnetically induced spin depolarization measurements using the n2EDM apparatus. This method is also used to exploit sensitivity to the storage properties of the materials used to trap ultracold neutrons, specifically, whether collisions are specular or diffuse. To do so, we utilize tomat simulation to map storage properties to correlation times of the ultracold neutrons to induced magnetic nonuniformities. We highlight the sensitivity of this new technique by comparing the two different storage chambers of the n2EDM experiment, which host different ultracold neutron energy spectra. This method should prove to be invaluable to assess systematic effects in experiments utilizing spin-polarized systems with precise magnetic control and long spin-spin coherence time relative to the observation time, such as neutron electric dipole moment and neutron lifetime experiments worldwide.

We demonstrate deterministic preparation of arbitrary two-component product states of fermionic ${}^6\mathrm{Li}$ atoms in an $8\times 8$ optical tweezer array, achieving motional ground-state fidelities above 98.5%. Leveraging the large differential magnetic moments for spin-resolution, with parallelized site- and number-resolved control, our approach addresses key challenges for low-entropy quantum state engineering. Combined with high-fidelity spin-, site-, and density-resolved readout within a single $20\mathrm{\mu s}$ exposure, and 3 s experimental cycles, these advances establish a fast, scalable, and programmable architecture for fermionic quantum simulation.

The Berezinskii-Kosterlitz-Thouless (BKT) transition is an archetypal example of a topological phase transition, which is driven by the proliferation of vortices. In this Letter, we analyze the persistence of the BKT transition in the XY model under the influence of long-range algebraically decaying interactions of the form $\sim 1/r^{2+\sigma }$. The model hosts a magnetized low temperature phase for sufficiently small $\sigma$. Crucially, in the presence of long-range interactions, spin waves renormalize the interaction between vortices, which stabilizes the BKT transition. As a result, we find that there is no direct transition from the magnetized to the disordered phase and that the BKT transition persists for arbitrary long-range exponents, which is distinct from previous results. The key methodological advance is the inclusion of coupling between spin wave and topological excitations. We do this by developing Landau-Peierls–type arguments and using higher-order renormalization group calculations, obtaining compatible results. We emphasize that Landau-Peierls–type arguments are a powerful tool for analyzing continuous spin models. We discuss the relevance of our findings for current Rydberg atom experiments, and highlight the importance of long-range couplings for other types of topological defects.

We present a single-quench protocol that generates unitary $k$-designs with minimal control. A system first evolves under a random Hamiltonian $H_1$; at a switch time $t_s\ge t_{\mathrm{Th}}$ (the Thouless time), it is quenched to an independently drawn $H_2$ from the same ensemble and then evolves under $H_2$. This single quench breaks residual spectral correlations that prevent strictly time-independent chaotic dynamics from forming higher-order designs. The resulting ensemble approaches a unitary $k$-design using only a single control operation—far simpler than Brownian schemes with continuously randomized couplings or protocols that apply random quenches at short time intervals. Our analytical results are derived for Gaussian unitary random matrices, while our numerical demonstrations are carried out primarily in the Sachdev-Ye-Kitaev model. Beyond offering a direct route to Haar-like randomness, the protocol yields an operational, measurement-friendly definition of $t_{\mathrm{Th}}$ and provides a quantitative diagnostic of chaoticity. It further suggests symmetry-resolved and open-system extensions, circuit-level single-quench analogs, and applications to randomized measurements, benchmarking, and tomography.

Periodic (Floquet) driving enables Hamiltonian engineering and nonequilibrium phases, but interacting systems eventually heat by absorbing energy from the drive. Disorder can greatly delay this process, yielding long-lived prethermal plateaus. Here, we show that this protection can fail when pulse-train control introduces a second driving frequency and when the disorder fluctuates. Using a natural-abundance ${}^{13}\mathrm{C}$ nuclear-spin network in diamond, we observe sharp peaks in the late-time heating rate at the double- and triple-spin-flip resonance conditions predicted by bimodal Floquet interference and track their evolution with drive frequency. A switching-noise model attributes the resonant absorption to stochastic electron-spin dynamics that intermittently tune rare nuclear clusters into multiphoton resonance. Our results reveal a resonance-activated limit for disorder-stabilized Floquet phases and suggest new routes to dc-field quantum sensing based on an abrupt breakdown of prethermalization.

The generation of spin magnetization by linear and nonlinear Edelstein effects has so far relied solely on electric fields. Here, we propose a distinct mechanism, the nonlinear magnetoelectric Edelstein effect (NMEE), in which electric and magnetic fields act cooperatively to produce spin magnetization. The NMEE comprises intrinsic and extrinsic components, both of quantum geometric origin, arising, respectively, from the spin-space Berry curvature dipole and the spin-space quantum metric dipole. Through symmetry analysis, we demonstrate that these two components play complementary roles: the intrinsic NMEE induces a Néel spin-orbit torque, whereas the extrinsic NMEE enables detection of Néel-vector reversal in $\mathcal{P}\mathcal{T}$-symmetric antiferromagnets, exemplified by CuMnAs. Moreover, the intrinsic NMEE persists even in insulating systems, as shown in the Kane-Mele model. Our findings establish a quantum-geometric route to manipulate and probe magnetic order, opening new directions for antiferromagnetic spintronics.

For a quantum field of arbitrary mass and spin in the static patch of de Sitter spacetime, the Euclidean partition function receives contributions from edge modes localized on the horizon, expressible in terms of the Harish-Chandra character of the de Sitter group. Considering the flat limit and summing over all string fields, we obtain the partition function of edge modes in string theory near the Minkowski-Rindler horizon. Application of the Kronecker limit formula naturally yields a modular invariant one-loop partition function. The resulting expression generalizes the edge contribution of a massive vector boson in a spontaneously broken gauge theory to the infinite tower in string theory. It is naturally ultraviolet finite and amenable to a state-counting interpretation.

We show that one-jettiness (${\tau }_1$) in color-singlet plus jet production suffers from superleading logarithms starting at order ${\alpha }_{\mathrm{s}}^4\ln (1/{\tau }_1{)}^6$ relative to the Born level. This is one logarithm more dominant than any previously identified superleading logarithms. The extra logarithm is not associated with additional poles, and is therefore consistent with the factorization of universal parton distribution functions at scale ${\tau }_{1}Q$, where $Q$ is the hard scale.

A superfluid flows without friction below a critical velocity, exhibiting zero drag force on impurities. Above this threshold, superfluidity breaks down, and the internal energy is redistributed into incoherent excitations such as vortices. We demonstrate that a mobile, finite-mass impurity immersed in a flowing two-dimensional paraxial superfluid of light can swim against the superfluid current when the critical velocity is exceeded. This self-propulsion is achieved by the periodic emission of vortex-antivortex pairs downstream, which impart an upstream recoil momentum that results in a net propulsive force. Analogous to biological systems that minimize effort by exploiting wake turbulence, the impurity harnesses this vortex backreaction as a passive mechanism of locomotion. Based on a simple theoretical model, we quantitatively describe how this mechanism depends on the impurity geometry and the surrounding flow velocity. Our findings establish a fundamental link between internal-energy dissipation in quantum fluids and concepts of self-propulsion in active-matter systems and open new possibilities for exploiting quantum vortices for controlled transport at the microscale.

Optical skyrmions are topological textures of electromagnetic fields with promising applications in information processing, transport, and storage. Exquisitely tailoring the optical fields of diverse physical quantities has expanded the family of skyrmions, yet such skyrmions only exhibit a single-quantity texture in free space. Herein, dual skyrmionic textures concurrently portraying spin and Poynting vectors are unveiled in the tight focus of an annular second-order circularly polarized vortex beam. The focal electric and magnetic fields exhibit an elongated and identical spatial distribution but a phase difference of $\pi /2$, leading to dual skyrmionic textures with vector orientations that are either opposite or identical, depending on the handedness of the incident beam. Unlike conventional optical skyrmions that are exclusively regarded as quasiparticles distributed in a two-dimensional plane, a skyrmionic tube structure that extends over a longitudinal depth approaching $10\lambda$ while preserving its topology is demonstrated. Our Letter enhances the comprehensiveness of optical skyrmions and paves the way toward their practical applications by bolstering skyrmion-matter interactions.

Accurate ionization balance of gold plasmas in nonlocal thermodynamic equilibrium is essential for understanding the physics involved in inertial confinement fusion (ICF) hohlraums, where the persistent “drive deficit” issue may stem from an overestimation of the emission and absorption opacity of gold plasmas. Predicting the charge state distribution (CSD) of gold plasmas at temperatures of several keV poses considerable challenges as the ionization stages with open N and M shells are predominantly populated. In this study, we performed benchmark calculations for the CSD of gold plasmas at extremely high temperatures up to 8 keV. We used a rate equation based on the relativistic configuration approximation, taking into account electronic configurations with electron excitations up to a principal quantum number of $n=12$, resulting in over 10 million atomic states, which have not been previously achieved. A Monte Carlo algorithm was developed to efficiently solve these large-scale rate equations under the steady-state approach. By carefully considering the highly excited atomic states, we achieved convergence in the CSDs. The highly excited atomic states with maximum principal quantum numbers $n=8–12$ provide crucial dielectronic recombination channels and have a substantial impact on the ionization balance at a temperature of 8 keV and an electron density of ${10}^{21}{\mathrm{cm}}^{-3}$. This research lays the groundwork for accurately determining CSDs of gold plasmas in ICF hohlraums, contributing to a better understanding of the physical origins of the “drive deficit” problem.