Source-independent quantum secret sharing (SI QSS), while essential for secure multi-user cryptographic operations in quantum networks, faces significant implementation challenges stemming from the inherent complexity of generating and distributing multipartite entangled states. Recently, a resource-efficient SI QSS protocol utilizing entangled photon pairs combined with a postmatching method has been proposed to address this limitation. In this Letter, we report an experimental demonstration of this protocol using high-fidelity polarization-entangled photon pairs in a star topology. For a three-user network, we obtain secure key rates of 21.18, 4.69, and 1.71 kbps under single-user channel losses of 7.6, 10.9, and 12.9 dB respectively. Furthermore, under conditions of equal channel loss per user, we achieve secure key rates of 6.97, 6.46, and 5.88 kbps for three-, four-, and five-user scenarios respectively. These results demonstrate the advantageous independence of the key rate from the number of users. Our Letter paves the way for large-scale deployment of SI QSS in multiuser quantum networks.

In electromagnetism, linearized general relativity, and other contexts, previous work has shown that the laws of motion which govern compact, self-interacting bodies can be obtained by applying “Detweiler-Whiting prescriptions” to the laws of motion that govern test bodies. These prescriptions replace any field that appears in a test-body law of motion with a certain effective field which is a quasilocal functional of the physical variables—a functional that can be interpreted as a regularization procedure in a point-particle limit. We generalize these results, presenting a formalism that allows Detweiler-Whiting prescriptions to be be directly derived for extended bodies, even in nonlinear field theories. If a generating functional with particular properties can be constructed, we find effective linear and angular momenta which evolve via Mathisson-Papapetrou-Dixon equations involving appropriate effective fields. These equations implicitly incorporate all self-force, self-torque, and extended-body effects. Although our main focus is on bodies coupled to nonlinear scalar fields, we also remark on the gravitational case.

We present a search for the rare flavor-changing neutral-current decay $B^0\to K^{*0}{\tau }^{+}{\tau }^{-}$ with data collected by the Belle II experiment at the SuperKEKB electron-positron collider. The analysis uses a $365{\mathrm{fb}}^{-1}$ data sample recorded at the center-of-mass energy of the $\mathrm{\Upsilon }(4S)$ resonance. One of the $B$ mesons produced in the $\mathrm{\Upsilon }(4S)\to B^0{\overline{B}}^0$ process is fully reconstructed in a hadronic decay mode, while its companion $B$ meson is required to decay into a $K^{*0}$ and two $\tau$ leptons of opposite charge. The $\tau$ leptons are reconstructed in final states with a single electron, muon, charged pion or charged $\rho$ meson, and additional neutrinos. We set an upper limit on the branching fraction of $\mathcal{B}(B^0\to K^{*0}{\tau }^{+}{\tau }^{-})<1.8\times {10}^{-3}$ at the 90% confidence level, which is the most stringent constraint reported to date.

We probe resonant dipolar interactions between ultracold ${}^{40}\mathrm{K}{}^{87}\mathrm{Rb}$ molecules and Rydberg ${}^{87}\mathrm{Rb}$ atoms in an optically trapped ensemble. Through state-selective ionization detection of the KRb molecules, we observe resonant energy transfer at 2.227 GHz from Rydberg atoms to molecules under a tunable external electric field. We measure a broadening up to 3.5 MHz, for the Rb Rydberg excitation spectrum, which matches a Monte Carlo simulation that describes a Rydberg atom and neighboring molecules evolving under a dipole-dipole interacting Hamiltonian. The demonstrated interspecies dipolar interaction is a key ingredient for hybrid Rydberg-polar molecule systems, where the advantages of each system can be leveraged and combined.

We investigated resonant multiphoton excitation of high-angular-momentum doubly excited states of the strontium atom, a quasi-three-body Coulomb system, both experimentally and theoretically. A series of highly doubly excited states converging to the double ionization threshold was identified and reproduced by first-principles calculations, which provided access to the two-electron wave functions of the resonances. In these states, the outer electron is dynamically localized at large distances by pendulumlike oscillations of the inner electron across the nucleus. A complementary simple molecularlike adiabatic model offers a clear interpretation of the correlated two-electron motion and suggests that the series is a general feature of highly doubly excited states of atoms and molecules.

We investigate the physics of ultracold dipolar molecules using path-integral quantum Monte Carlo simulations, and construct the complete phase diagram extending from weak to strong interactions and from small to mesoscopic particle numbers. Our calculations predict the formation of self-bound quantum droplets at interaction strengths lower than previous estimates for molecular condensates. Strikingly, we observe that, for stronger interactions, the oblate quantum droplet transitions to a two-dimensional sheet or superfluid membrane with a thickness of a single molecule. As interactions are increased further the system continually loses superfluidity while correlations develop, and is eventually found to undergo a transition to a crystalline monolayer that remains self-bound without external confinement. The spontaneous formation of such two-dimensional phases from a three-dimensional quantum gas is traced back to the peculiar anisotropic form of the dipole-dipole interaction generated by microwave dressing of rotational molecular states. For sufficiently large particle numbers, crystallization takes place for comparably low interaction strengths that do not promote two-body bound states and should thus be observable in ongoing experiments without limitations from three-body recombination.

Scanning probe microscopy with multiqubit sensors offers the potential to improve imaging speed and measure previously inaccessible quantities, such as two-point correlations. We develop a multiplexed quantum sensing approach with scanning probes containing two nitrogen-vacancy (NV) centers at the tip apex. A shared optical channel is used for simultaneous qubit initialization and readout, while phase- and frequency-dependent microwave spin manipulations are leveraged for demultiplexing the optical readout signal. Scanning dual-NV magnetometry is first demonstrated by simultaneously imaging multiple field projections of a ferrimagnetic racetrack device. Then, we record the two-point covariance of spatially correlated field fluctuations across a current-carrying wire. Our multiplex framework establishes a method to investigate a variety of spatiotemporal correlations, including phase transitions and electronic noise, with nanoscale resolution.

Sheared flow increases the reactivity of fusion plasma. In unmagnetized plasma with flow gradients comparable to the mean free path of reacting ions, fusion reactivity can be more than doubled. The effect is of particular relevance to inertial confinement fusion (ICF), where it allows implosion kinetic energy to contribute to the fusion burn even before thermalizing. Because colder fuel stops alpha particles more quickly, ignition is possible in a smaller volume, substantially reducing energy requirements in fast-ignition designs.

Nanopores evolve in dealloying to dictate alloy corrosion while enabling the creation of functional metallic nanomaterials. Yet, the nanoscale dynamics of the porosity evolution have long eluded experimental characterizations. With aberration-corrected transmission electron microscopy, we reveal the evolution of nanoporous Co from the vapor phase dealloying (VPD) of $\gamma$-CoZn across scales. The in situ characterization confirms key aspects of the dealloying mechanism based on macroscopic characterizations and simulations, including dissolution by repeated step flow and vacancy-cluster nucleation as well as ligament and pore bifurcation. It also separates the step flow kinetics from that of VPD, revealing that a bond energy difference between the alloy constituents can determine the dealloying kinetics and affect the morphology. The findings refine the classic dealloying theory for potentially new fabrications.

Rhombohedral graphene (RG) has emerged as a promising platform for exploring exotic quantum phenomena, such as quantum magnetism, unconventional superconductivity, and fractional quantum anomalous Hall effects. Despite its potential, atomic-scale investigations of RG remain limited, hindering a detailed microscopic understanding of the origins of these correlated states. In this Letter, we employ scanning probe microscopy and spectroscopy to probe the intrinsic electronic states in trilayer and tetralayer RG. We identify a correlated insulating state with a gap up to 19 meV at the charge neutrality point in tetralayer RG, which is absent in the trilayer RG and Bernal stacking tetralayer. This gap is suppressed by applying a perpendicular magnetic field or doping the charge carrier density and does not exhibit intervalley coherence patterns. We attribute this phenomenon to a symmetry-broken layer antiferromagnetic state, characterized by ferrimagnetic ordering in the outermost layers and antiferromagnetic coupling between them. To further investigate this magnetic correlated state, we conduct local scattering experiments. Within the correlated regime, a threefold symmetric pattern emerges around a possible nonmagnetic impurity, suggesting that nonmagnetic doping may induce a spin texture in the ferrimagnetic surface layers. Outside the correlated regime, Friedel oscillations are observed, allowing precise determination of the band dispersion in tetralayer RG. These findings provide atomic-scale evidences of zero-field correlations in RG and may be extended to study other exotic phases in RG.

We observe magnetic quantum oscillations in the heat capacity of the Kondo insulator ${\mathrm{YbB}}_{12}$. The frequency of these oscillations, $F=700\mathrm{T}$, agrees with that from magnetoresistance and torque magnetometry experiments for ${\mu }_{0}H>35\mathrm{T}$ in the Kondo insulating phase. Remarkably, the quantum-oscillation amplitudes in the heat capacity are substantial, with $\mathrm{\Delta }\tilde{C}/T\approx 0.5\mathrm{mJ}{\mathrm{mol}}^{-1}{\mathrm{K}}^{-2}$ at 0.8 K, accounting for 13% of the known linear heat-capacity coefficient $\gamma$. Double-peak structures of quantum-oscillation amplitudes due to the distribution function of fermions were identified and used to determine the value of the effective mass from the heat capacity, which agrees well with that from torque magnetometry. These observations support bulk charge-neutral fermions contributing to the quantum oscillations in ${\mathrm{YbB}}_{12}$.

The optical pump-probe technique is a common tool for the investigation of ultrafast spin dynamics, which usually utilizes single-diode detection averaging the dynamics over the pumped area. Using an ultrafast imaging technique, we show experimentally that a femtosecond laser pulse with a gradient distribution of intensity efficiently excites strongly inhomogeneous spin dynamics on spatial scales much smaller than the pump spot size. The mechanism responsible for the inhomogeneous distribution is based on temperature gradients and corresponds to a sign change of the torque derivative in different areas of the pump. We argue that the observed phenomenon is general for the systems with competitive magnetic anisotropies. Overlooking this effect in the majority of pump-probe experiments can result in a dramatic underestimate of the lifetime and amplitude of the laser-induced spin dynamics.

Through experiments and a proposed model, we revealed for the first time why electrons laterally migrate within the ${\mathrm{Si}}_3{\mathrm{N}}_4$ charge trap layer during the programming of flash memory devices. The proposed thermally assisted trap-to-band tunneling emission model well explained the measured electric field and temperature effects on the lateral migration of electrons. The proposed model was emulated in a commercial technology computer-aided design tool through a user interface, enabling accurate physical analysis. This model can be used to design devices utilizing lateral migration of electrons or to analyze various phenomena in vertical NAND flash memory, such as space program and Z interference.

Active soft matter frequently shows motility-induced phase separation, where self-propelled particles condensate into clusters with an inner liquidlike structure. Such activity may also result in motility-induced crystallization into clusters with an inner crystalline structure. We derive a higher-order active phase-field-crystal model and employ it to study the interplay of passive (i.e., thermodynamic) and active (i.e., motility-induced) condensation or evaporation and crystallization or melting. Stability and morphological phase diagrams indicate the various occurring phase coexistences and transitions, e.g., the destruction of passive clusters in the case of a density-independent effective velocity and the possible creation of active clusters in the case of a density-dependent effective velocity. Finally, simple and complex rotating crystallites are discussed, including states of time-periodic chirality.

We present a general approach to error detection of bosonic quantum error-correction codes via an adaptive quantum phase estimation algorithm assisted by a single ancilla qubit. The approach is applicable to a broad class of bosonic codes whose error syndromes are described by symmetry or stabilizer operators, including the rotation-symmetric codes and Gottesman-Kitaev-Preskill (GKP) codes. The detection precision scales inversely with the total evolution time and thus reaches the Heisenberg limit. We numerically demonstrate the approach for several examples, such as detecting bosonic excitation loss errors in high-order cat or binomial codes and displacement errors in finite-energy GKP codes. We also extend the approach to efficiently generate arbitrary Fock states. Our schemes are feasible in present-day experiments.

In this Letter we propose a novel relationship between topology and damage propagation in Maxwell lattices that redefines fracture as a functional design feature rather than mere degradation. We demonstrate that topologically protected modes, inherently robust against perturbations, localize along lattice discontinuities and govern the mechanical response. By precisely engineering the microstructure, we direct these modes to control stress distributions and trigger predictable, controlled damage. Our findings, validated through comprehensive numerical simulations and experiments, advance our understanding of nontrivial mechanical responses in Maxwell lattices and establish a clear framework for designing materials with improved fracture energy. This Letter paves the way for further exploration of topology-driven phenomena in mechanical systems and promises a new direction in the design of robust materials.