We construct a minimal model of interacting fermions establishing a ferromagnetic insulating phase. It is based on the Hubbard model on a trimerized triangular lattice in the regime of $t\gg |t^{\prime }|>0$ with $t$ and $t^{\prime }$ the intra- and intertrimer hopping amplitudes, respectively. At the $\frac{1}{3}$-filling, each trimer becomes a triplet spin-1 moment, and the intertrimer superexchange is ferromagnetic with $J=-\frac{2}{27}(t^{\prime 2}/t)$ in the limit of $U/t=+\infty$. As $U/t$ becomes finite, the antiferromagnetic superexchange competes with the ferromagnetic one. The system enters into a frustrated antiferromagnetic insulator when $\lambda >U/t\gg 1$ where $\lambda$ is a constant at the order of 10. In contrast, a similar analysis to the trimerized Kagome lattice shows that only the antiferromagnetic superexchange exists at $\frac{1}{3}$-filling.

The selection of stacking order in a broad range of close-packed polymorphic materials remains a challenging enigma. Using in situ cryogenic transmission electron microscopy, we uncover the atomistic mechanisms governing the vapor deposition growth of ice. We find that the heterogeneous ice nucleation and growth undergo recrystallization accompanied by bifurcation, reflecting a coherent epitaxial transition from a cubic-ice embryonic core to hexagonal-ice prismatic dendrites, with intermediate stacking-disordered layers serving as a dynamic fluctuating bridge. Supported by molecular dynamics simulations, these phenomena are attributed to a surface-constrained, symmetry-breaking crystallization preference aligned with the principle of minimizing free energy. Our results highlight the critical role of the combined effects of surface and symmetry in shaping ice crystallization, providing fresh insights into crystal growth mechanisms and guiding principles for the design of advanced materials.

Contextuality is a key characteristic that separates quantum from classical phenomena and an important tool in understanding the potential advantage of quantum computation. However, when assessing the quantum resources available for quantum information processing, there is no formalism to determine whether a set of states can exhibit contextuality and whether such proofs of contextuality indicate anything about the resourcefulness of that set. Introducing a well-motivated notion of what it means for a set of states to be contextual, we establish a relationship between contextuality and antidistinguishability of sets of states. We go beyond the traditional notions of contextuality and antidistinguishability and treat both properties as resources, demonstrating that the degree of contextuality within a set of states has a direct connection to its level of antidistinguishability. If a set of states is contextual, then it must be weakly antidistinguishable and vice versa. However, critical contextuality emerges as a stronger property than traditional antidistinguishability.

The simulation of quantum field theories, both classical and quantum, requires regularization of infinitely many degrees of freedom. However, in the context of field digitization (FD)—a truncation of the local fields to $N$ discrete values—a comprehensive framework to obtain continuum results is currently missing. Here, we propose to analyze FD by interpreting the parameter $N$ as a coupling in the renormalization group (RG) sense. As a first example, we investigate the two-dimensional (2D) classical $N$-state clock model as a ${\mathbb{Z}}_N$ FD of the $U(1)$ symmetric $XY$ model. Using effective field theory, we employ the RG to derive generalized scaling hypotheses involving the FD parameter $N$, which allows us to relate data obtained for different $N$-regularized models in a procedure that we term field digitization scaling (FDS). Using numerical tensor-network calculations at finite bond dimension $\chi$, we further uncover an unconventional universal crossover around a low-temperature phase transition induced by finite $N$, demonstrating that FDS can be extended to describe the interplay of $\chi$ and $N$. Finally, we analytically prove that our calculations for the 2D classical-statistical ${\mathbb{Z}}_N$ clock model are directly related to the quantum physics in the ground state of a $(2+1)\mathrm{D}$ ${\mathbb{Z}}_N$ lattice gauge theory, which serves as a FD of compact quantum electrodynamics. Our Letter thus paves the way for applications of FDS to quantum simulations of more complex models in higher spatial dimensions, where it could serve as a tool to analyze the continuum limit of digitized quantum field theories.

We address the metrological problem of estimating collective stochastic properties imprinted on a network of quantum sensors. Canonical examples include center-of-mass quadrature fluctuations in a system of bosonic modes and correlated dephasing in an ensemble of qubits (e.g., spins), bosons, or fermions. We develop a theoretical framework to determine the limits of correlated (weak) noise estimation with quantum sensor networks and reveal the requirements for entanglement advantage. Notably, an advantage emerges from the synergistic interplay between quantum correlations of the sensors and “classical” correlations of the noises. We determine optimal entangled probe states and identify a sensing protocol—reminiscent of a many-body echo—that achieves the fundamental limits of measurement sensitivity for a broad class of problems, unveiling a route toward entanglement-enhanced metrology of correlated many-body phenomena.

We propose an $\mathrm{AdS}\times \mathrm{S}$ factorization formula at the level of the generating function for correlators with arbitrary Kaluza-Klein configurations and implement it in the supergravity limit of $\mathcal{N}=4$ supersymmetric Yang-Mills theory. By incorporating this mechanism into Mellin space bootstrap, together with an observed $Z_2$ symmetry under $\mathrm{AdS}\leftrightarrow \mathrm{S}$, we manage to simultaneously work out unified formulas both for all five-point half-BPS correlators and for all four-point correlators with one superdescendant. This $\mathrm{AdS}\times \mathrm{S}$ bootstrap method is directly applicable to generic multipoint computation at tree level.

We show that piezoelectric materials can be used to source virtual QCD axions, generating a new axion-mediated force. Spontaneous parity violation within the piezoelectric crystal combined with time-reversal violation from aligned spins provide the necessary symmetry breaking to produce an effective in-medium scalar coupling of the axion to nucleons up to seven orders of magnitude larger than that in vacuum. We propose a detection scheme based on nuclear spin precession caused by the axion’s pseudoscalar coupling to nuclear spins. This signal is resonantly enhanced when the distance between the source crystal and the spin sample is modulated at the spin precession frequency. Using this effect, future experimental setups can be sensitive to the QCD axion in the unexplored mass range from ${10}^{-5}\mathrm{eV}$ to ${10}^{-2}\mathrm{eV}$.

Recent experimental data show an unexpectedly large spin alignment of $\varphi$ mesons in high-energy heavy-ion collisions, which can be explained by short-distance fluctuations of strong-force fields (vector $\varphi$ fields) within the constituent-quark model. We calculate the hyperon spin correlations within the same model, taking into account hydrodynamic effects and a $\varphi$ field fluctuating in space-time according to a Gaussian distribution. The $\mathrm{\Lambda }\overline{\mathrm{\Lambda }}$ spin correlation induced by the $\varphi$ field is shown to be negative as opposed to that of $\mathrm{\Lambda }\mathrm{\Lambda }$ or $\overline{\mathrm{\Lambda }}\overline{\mathrm{\Lambda }}$. We thus propose a new net spin-correlation observable as a sensitive probe to separate strong-force effects from hydrodynamic ones. With the strength of the field fluctuations extracted from the observed $\varphi$ spin alignment, we predict the collision-energy dependence of the hyperon spin correlations and also investigate the dependence of the net spin correlation on azimuthal-angle and rapidity difference.

Delayed $\gamma$-ray spectroscopy was performed for evaporation residues produced in the ${}^{58}\mathrm{Ni}+{}^{96}\mathrm{Ru}$ reaction. A new isomer in ${}_{70}{}^{150}\mathrm{Yb}$ ($Z=70$, $N=80$) with a half-life of $0.62(5)\mathrm{\mu }\mathrm{s}$ was identified at an excitation energy of 2872(2) keV. Its spin-parity is assigned as (${10}^{+}$) and a decay scheme is proposed based on a strong analogy with that of the isotonic ${}_{68}{}^{148}\mathrm{Er}$. Previously, the ${10}^{+}$ isomers were observed in the $N=80$ even-$Z$ isotones from the neutron-rich ${}_{46}{}^{126}\mathrm{Pd}$ to the neutron-deficient ${}_{68}{}^{148}\mathrm{Er}$. For the first time, by combining experimental data and comprehensive large-scale shell-model calculations, we clearly identify the configurations of these isomers and demonstrate that they all exhibit seniority structures. These findings firmly establish a configuration change in the ${10}^{+}$ isomeric chain, from a pair of maximally aligned $1h_{11/2}$ neutrons (holes) to a pair of maximally aligned $1h_{11/2}$ protons around the $Z=64$ subshell closure. This transition serves as a unique isomeric relay underpinning the persistence of the isomeric chain.

The Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction and Efimov physics are two distinct quantum phenomena in condensed matter and nuclear physics, respectively. The RKKY interaction describes correlations between impurities mediated by an electron gas, while Efimov physics describes universal bound states of three particles with resonant interactions. Recently, both effects have been observed in Bose-Fermi mixtures in the weak and resonant interaction regimes, respectively. Intriguing conjectures exist to elucidate how the two phenomena meet in the transition regime where the mixture is strongly interacting. In this Letter, we explore the RKKY-Efimov transition in a mixture of bosonic ${}^{133}\mathrm{Cs}$ and fermionic ${}^6\mathrm{Li}$ near a tunable interspecies Feshbach resonance. From dispersion and relaxation measurements, we find that the transition is highlighted by a fermion-mediated scattering resonance between Cs atoms and a weaker resonance on Li atoms. These resonances represent reactive scattering of Cs and Li atoms in the many-body regime, which reduce to an Efimov resonance in the thermal gas regime. Our observation demonstrates the intriguing interplay of two-, three-, and many-body physics in a Bose-Fermi mixture that connects condensed matter physics, nuclear physics, and quantum many-body chemistry.

We investigate the real-time buildup of short-range correlations in a nondegenerate ultracold Bose gas near a narrow Fano-Feshbach resonance. Using rapid optical control, we quench the closed-channel molecular energy to resonance on submicrosecond timescales and track the evolution of the two-body contact through photodissociation losses. Repeated pulse sequences enhance sensitivity to early-time two-body losses and reveal long-lived coherence between atom pairs and molecular states. The observed dynamics are accurately reproduced by our dynamical two-channel zero-range theory, which explicitly accounts for the resonance’s narrow width and finite closed-channel decay, establishing a predictive framework for correlation dynamics in quantum gases near Fano-Feshbach resonances.

Casimir force, stemming from quantum fluctuation prominent at nanoscale, can cause notable motion or deformation of objects. While Casimir-induced rigid-body motion has been successfully described, quantifying elastic deformation remains challenging due to the poorly understood Casimir stress. By advancing a dedicated boundary element method, we find the Casimir stress concentration similar to the classical mechanics counterpart. Using a wedge-plate system as a prototype, we show that the Casimir stress on wedge slope exerted by a noncontacting plate is concentrated near the vertex, exceeding the pressure predicted by proximity-force approximation by orders of magnitude. Such an effect is attributed to the disrupted principal Maxwell stress trajectories by geometric singularity. Both the transformation optics analysis and the normalized stress distribution indicate a scale invariance of the Casimir stress. This Letter not only highlights the significant geometric effect on Casimir stress but also facilitates Casimir-based elastic mechanics.

Moiré materials provide exciting platforms for studying the interplay of strong electronic correlation and large magnetic flux effects. We study the lightly doped Hofstadter-Hubbard model on a triangular lattice through the large-scale density matrix renormalization group and determinantal quantum Monte Carlo simulations. We find strong evidence for a robust chiral superconducting (SC) phase with dominant power-law pairing correlations and a quantized spin Chern number. The SC phase emerges at very weak interaction and grows stronger at intermediate interaction strengths ($U$) for a wide range of hole doping. We also discuss the possible distinct nature of the normal state in different $U$ regimes. Our Letter provides theoretical insights into the emergence of topological superconductivity from doping topological Chern bands or magnetic-flux-induced chiral spin liquid states of Moiré materials.

Ferromagnetic topological insulators in the quantum anomalous Hall (QAH) regime host chiral, dissipationless edge states whose propagation direction is determined by the internal magnetization. Under suitable conditions, a strong electrical bias can induce magnetization reversal, and thus flip the propagation direction. In this Letter, we perform time-resolved measurements to investigate the switching dynamics. Our results reveal characteristics consistent with a disordered magnetic landscape and demonstrate that the reversal process is thermally activated, driven by Joule heating during current pulses. The understanding of the magnetization dynamics in QAH systems opens pathways for local, controlled manipulation of chiral edge states via thermal effects.

Non-Hermitian systems give rise to nontrivial phenomena due to their ability to exhibit peculiar spectral singularities known as exceptional points. Especially, the dynamical encirclement of exceptional points in a system parameter space enables chiral state switching. Although this chiral behavior can be effectively controlled in two-mode structures, extending such control to higher-dimensional systems with multiple exceptional points presents significant challenges, particularly when aiming to steer the system toward a specific target state, a capability crucial for advancing such fields as optical communication and quantum information processing. In this work, we overcome this challenge by experimentally demonstrating a genuine programmable symmetric-asymmetric multistate switching in a four-mode optical system. This is achieved through the controlled dynamic interplay between exceptional and diabolic points in the Hamiltonian spectrum. Our results lay the groundwork for the practical development of advanced light manipulation protocols in multimode photonic setups.

We demonstrate here that a chain of bilayer graphene quantum dots (BLGQDs) can realize topological quantum matter by effectively simulating a spin-1 chain that hosts the Haldane phase within a specific range of parameters. We describe a chain of BLGQDs with two electrons per dot using an atomistic tight-binding model combined with exact diagonalization to solve the interacting few-electron problem. Coulomb interactions and valley-mixing effects are treated within a single microscopic framework, allowing us to systematically investigate spin and valley polarization transitions as functions of interaction strength and external tuning parameters. We calculate the low energy states for single and double QDs as a function of the number of electrons, identifying regimes of highly correlated multielectron states. We confirm the presence of a spin-1 ground state for two electrons. Then, we explore two coupled QDs with four electrons and extend the analysis to QD arrays. Using a mapping of the BLGQD chain to an effective bilinear-biquadratic (BLBQ) spin model, we demonstrate that BLGQD arrays can work as a quantum simulator for one-dimensional spin chains with emergent many-body topological phases.

We measured the thermal conductivity of the rare-earth orthoferrites, $R{\mathrm{FeO}}_3$, where $R=\mathrm{Eu}$, Gd, Tb, Dy, Ho, Er, Tm, and Yb from 3 to 300 K and see an anomalous strong suppression for ${\mathrm{TmFeO}}_3$ over most of the temperature range. Using a Debye thermal transport model, we demonstrate that this suppression is due to resonant scattering between phonons and the ${\mathrm{Tm}}^{3+}$ $4f$ singlet crystal field levels. The implications of these results are discussed in the context of thermal conductivity studies in quantum magnets.