The entanglement of quantum systems is commonly restricted by their coupling Hamiltonian and initial state properties. Here, we prove by exact analysis of tunnel-coupled bosonic field modes that factorized multiboson two-mode states can become fully entangled via stroboscopic sign flips of the two-mode coupling. Their entanglement can exponentially grow with the number of flips. With the exception of specific prohibitive states that are invariant under such sign-flip control, this effect universally applies to two-mode state preparation. Remarkably, this linear control may provide entanglement resources for diverse quantum technological applications by readily available means.

Non-Hermitian systems host phenomena absent in Hermitian physics, but realizing Hamiltonians with intrinsic non-Hermitian properties remains challenging. The theoretical method of non-Hermitian parent Hamiltonian (NH-PH) enables the construction of a non-Hermitian system from a pair of matrix product states (MPSs) with tailored properties. Here, we report the first experimental generation of NH-PHs. This generation starts from MPSs that represent asymmetric Affleck-Kennedy-Lieb-Tasaki states. The construction is validated with single photons via imaginary-time evolution of the generated NH-PH to obtain its left and right ground states. We then characterize the properties of the system by measuring four different order parameters that probe non-reciprocal correlations, chiral imbalance, and conventional antiferromagnetic correlations. Furthermore, extending the framework to a larger system with a different model, we observe an intrinsic non-Hermitian phase transition, manifested by abrupt jumps of an order parameter when the designated zero-energy modes cease to be the globally lowest-energy states. Our Letter provides the first experimental realization and characterization of non-Hermitian Hamiltonians with controllable and customizable properties, opening new avenues for exploring intrinsic non-Hermitian phenomena across diverse physical platforms.

Quantum error correction is indispensable for scalable quantum computation. Although encoding logical qubits substantially enhances noise resilience, achieving logical error rates low enough for practical algorithms remains challenging on existing hardware. Here, we introduce argument reweighting, a simple and broadly applicable postselection decoding strategy that boosts the performance of maximum-likelihood-type decoders, including minimum-weight perfect matching and belief-propagation families. The method suppresses logical errors by performing additional decoding rounds under reweighted error models, enabling acceptance of high-confidence syndrome outcomes. Circuit-level simulations across multiple decoders and qLDPC codes show that argument reweighting substantially suppresses logical errors, requiring a rejection rate of only $1.44\times {10}^{-5}$ to reduce the logical error rate by almost 2 orders of magnitude for the $[[144,12,12]]$ bivariate bicycle code. These results establish argument reweighting as a practical and resource-efficient approach for enhancing quantum fault tolerance.

Quantum gravity theories often modify spacetime symmetries. In particular, Lorentz invariance may be violated when approaching the Planck scale. Although the scales at which interactions occur in extensive air showers induced by ultra-high-energy cosmic rays in the atmosphere are many orders of magnitude below the Planck scale, these violations might still be observable. In this Letter, the fluctuations in the number of muons in the extensive air showers measured at the Pierre Auger Observatory are exploited, for the first time, to constrain Lorentz invariance violations. The bounds derived in the hadronic sector are the strongest ever obtained, and do not rely on assumptions about the mass composition of ultra-high-energy cosmic rays. The fluctuations in the number of muons constitute a new and powerful observable to further explore Lorentz invariance in a region of the parameter space not accessible to other observables.

A photon at $\mathcal{E}\simeq 251\mathrm{TeV}$ from GRB 221009A was detected by the Carpet Collaboration in 2022 using a partial dataset. Very recently, Carpet has completed its full data analysis reporting further support for its previous photon now at $\mathcal{E}=300_{-38}^{+43}\mathrm{TeV}$. Within standard propagation models, this observation is in strong tension with conventional expectations since such a photon is absorbed by the CMB. Further, we show that this detection is strongly disfavored within the explored scenarios involving axionlike particles (ALPs) alone. Instead, we find that the considered photon is compatible with specific Lorentz invariant violation (LIV) frameworks with the LIV scale obeying in the linear case ${\mathcal{E}}_{\mathrm{LIV},1}<1.22_{-0.22}^{+0.19}\times {10}^{21}\mathrm{GeV}$ at 95% CL and in the quadratic case ${\mathcal{E}}_{\mathrm{LIV},2}<2.03_{-0.22}^{+0.17}\times {10}^{13}\mathrm{GeV}$ at 95% CL. Finally, we outline scenarios where standard photon-ALP oscillations are combined with LIV-induced modifications of photon propagation, which provide a consistent interpretation of the observations of GRB 221009A concerning the highest-energy photons detected by the LHAASO and the Carpet Collaborations.

We study local quantum field theories in anti–de Sitter (AdS) space, with boundary conditions that break some of the bulk isometries. Specifically, we focus on conformal defects and we prove that their spectrum supports a displacement operator of protected dimension, despite the nonlocal nature of the conformal theory living at the boundary of AdS. If the defect breaks a global symmetry, a tilt operator is also present. The existence of a displacement was conjectured in Gabai et al. [J. High Energy Phys. 06 (2026) 029] for Wilson loops in Yang-Mills theories in AdS. Our proof is valid in general and applies, in particular, to defects in long-range models, as we discuss in various examples. In the bulk, the modes sourced by the protected operators have Compton wavelength of order of the AdS radius: they constitute the AdS analogue of the Goldstone bosons for the spontaneous breaking of the corresponding symmetries.

While most studies of the minimal type-I seesaw neglect the heaviest decoupled right-handed neutrino, assuming negligible contributions to neutrino masses and leptogenesis, we demonstrate that its cosmological role can be significant. When long-lived, the presence of this particle can substantially modify the charged lepton Yukawa equilibration temperature in the early universe, necessitating reassessment of lepton flavor effects in thermal leptogenesis and potentially shifting flavor regime boundaries. Additionally, we identify experimental probes, including neutrino oscillation measurements and gravitational wave observations to investigate this scenario. More broadly, the resulting modification of the cosmic expansion history carries implications beyond leptogenesis, impacting dark matter production and evolution, the matter-antimatter asymmetry generation, and the primordial gravitational wave spectrum.

This Letter presents a lattice quantum chromodynamics (QCD) determination of $\pi \pi \pi$ scattering amplitudes for the isospin-2 channel with angular momentum and parity $J^P=1^{+}$. The calculation is performed using unphysically heavy light-quark masses, corresponding to a pion mass of $m_{\pi }\approx 400\mathrm{MeV}$, for which the $\rho$ meson manifests as a narrow resonance. The analysis employs a previously developed formalism that nonperturbatively relates the finite-volume spectra of two- and three-pion systems to their infinite-volume scattering amplitudes. We combine earlier lattice QCD results for $\pi \pi$ systems with isospins 1 and 2 with new determinations of the isospin-2 three-pion finite-volume spectrum, obtained for three cubic, periodic lattice volumes with box length ranging from $\approx 4/m_{\pi }$ to $6/m_{\pi }$. These combined data constrain the low-lying partial waves of the infinite-volume three-pion $K$ matrix, from which we solve a set of coupled integral equations to extract the corresponding scattering amplitudes.

We report the first measurement of one- and two-point energy correlators within jets in transversely polarized proton-proton collisions at $\sqrt{s}=200\mathrm{GeV}$, using the STAR detector at the Relativistic Heavy Ion Collider. These observables quantify the energy-weighted angular distribution of single hadrons and hadron pairs within jets, respectively. Sizable spin-dependent asymmetries are observed for ${\pi }^{+}$, ${\pi }^{-}$, and ${\pi }^{+}{\pi }^{-}$ pairs, revealing the onset of nonperturbative dynamics at specific angular scales. By projecting the fragmentation dynamics onto Mellin moments, these measurements provide sensitivity to the nucleon’s transversity while minimizing uncertainties from nonperturbative fragmentation functions. These results establish energy correlators as a novel and precise probe of nucleon structure and open a promising avenue for three-dimensional nucleon tomography at the future Electron-Ion Collider.

Photoelectron circular dichroism (PECD) is a method where randomly oriented chiral molecules are photoionized due to irradiation by circularly polarized lasers, yielding large chiral signals in the photoelectron momentum distribution. Recently, PECD was explored with polarization-tailored light, such as bichromatic and noncollinear drivers, which still produces significant chiral signals. Yet, all known PECD configurations to date exhibit nonzero time-local chirality. That is, they are driven by an intrinsically helical light source. Nonetheless, “chiral” light can also be nonhelical if its chirality manifests on longer timescales (e.g., an optical centrifuge). It remains unknown whether PECD can arise from nonhelical coherent light. Here, we predict that chiral dichroism indeed emerges from nonhelical light by employing a train of linearly polarized intense laser pulses with a rotating polarization axis, which are phase coherent and time delayed. We find strong forward backward asymmetry in the model chiral molecule CBrClFH under a wide parameter regime that can be optimized up to $\sim 8\%$ by tuning delays between pulses, suggesting quantum interference. We directly show that the physical mechanism for this type of response differs from the standard PECD case, relying on a chiral excited electron attosecond wave packet evolving in the molecule, induced by the first linear pulse. Our Letter shows that multiple mechanisms can give rise to chiral dichroism on longer timescales and provides a novel approach for ultrafast chirality spectroscopy and coherent chiral wave-packet manipulation.

Some photonic crystals (PCs) with Dirac-like (or semi-Dirac) conical dispersions exhibit the property of double-zero index (DZI), which was previously thought to occur only at the center of the Brillouin zone ($\mathrm{\Gamma }$ point). Here, we demonstrate a general DZI effect in PCs, whose Dirac-like point can appear at multiple high-symmetry positions, with the previous conventional DZI at the $\mathrm{\Gamma }$ point being a special case. We theoretically elucidate the physical mechanism of the general DZI and summarize its necessary and sufficient conditions. We then experimentally confirm the photonic band and DZI effect in a general DZI PC with a semi-Dirac cone at the X point and demonstrate its unique transmission characteristics, including a 180° phase shift upon transmission, wave front flattening, and waveguiding with natural zero radiation loss. The extraordinary properties of general DZI PCs may open new avenues for designing directional light sources, phase-controlled optical switches, nanolasers, and on-chip photonic circuits.

Negative refraction provides a route to steer and focus wave energy flow, but it remains difficult to realize for coherent terahertz phonons. The difficulty stems from conventional dispersion-based mechanisms, which require strongly anisotropic or negative-curvature dispersions, while the long-wavelength acoustic phonons most favorable for coherent transport are nearly isotropic. Here, we overcome this limitation by introducing a momentum compensation mechanism mediated by discrete translational symmetry. Discrete translational symmetry parallel to the interface supplies a compensating tangential momentum, reopening transmitted channels beyond the conventional critical condition and enabling negative refraction when this compensation reverses the tangential component. Mode-resolved calculations for hBN/graphene heterostructures establish this mechanism in laterally stitched in-plane interfaces and show how twisted van der Waals moiré superlattices shift the negative-refraction window to lower frequencies. These results identify periodic crystalline interfaces as symmetry-engineered elements for terahertz phonon momentum conversion and wavefront control.

We have studied the magnetic properties of clinoatacamite ${\mathrm{Cu}}_2\mathrm{Cl}{(\mathrm{OH})}_3$, the parent compound of the quantum spin liquid candidate herbertsmithite and a long-standing puzzle among frustrated quantum magnets. As we reveal using density-functional theory, clinoatacamite belongs to the class of distorted kagome antiferromagnets with the kagome plane being embedded into a low-symmetry crystal structure. By means of thermodynamic measurements, muon spin rotation and relaxation, as well as neutron diffraction on single crystals, we find in zero magnetic field complex behavior below $T_{\mathrm{I}}=18.1\mathrm{K}$ which unfolds in three temperature regions I–III. We propose this complexity in multicritical clinoatacamite to arise from the competition of antiferromagnetic ordering modes from the underconstrained manifold of modes, which can lead to a metamagnetic texture in zero field.

We investigate the spin-$1/2$ $J_1–J_2$ triangular-lattice Heisenberg antiferromagnet in a magnetic field by combining large-scale density matrix renormalization group (DMRG) simulations with self-consistent spin-wave theory. The resulting field-coupling phase diagram reveals that quantum fluctuations stabilize coplanar order across the entire parameter range, giving rise to a characteristic sequence of magnetization plateaux. Near the quantum-spin-liquid window $0.06\lesssim J_2/J_1\lesssim 0.16$, which extends to magnetic field $B\sim J_1$, we identify overlapping $m=1/3$ and $m=1/2$ plateaux—a distinctive hallmark of the system’s proximity to the low-field spin-liquid regime. The excellent quantitative agreement between DMRG and self-consistent one-loop spin-wave calculations demonstrates that semiclassical approaches can reliably capture and parameterize the plateau phases of triangular quantum antiferromagnets.

We show that the Kasteleyn transition, the abrupt proliferation of infinite strings of defects in classical dimer and related models, can also be relevant for frustrated 2D quantum magnets. This is explicitly demonstrated in a phase of the spin-$1/2$ Heisenberg diamond-decorated honeycomb lattice where a family of exact eigenstates built as products of dimer and plaquette singlets can be mapped onto the dimer coverings of the honeycomb lattice. The low-temperature properties of this phase are accurately described by an effective dimer model with anisotropic activities and a small, tunable density of monomers, leading to an arbitrarily sharp crossover version of the Kasteleyn transition. The generalization to other geometries and the possibility of realizing this model in organometallic compounds are briefly discussed.

Resonant coupling of a vibration to a cavity mode has been reported to dramatically modify spontaneous Raman scattering, but subsequent studies have produced conflicting results. In this Letter, we develop a microscopic quantum framework that captures the spatial structure of polaritonic modes. In a homogeneously filled cavity, spatial overlap between polaritons and cavity resonances enforces selection rules that suppress the initially reported polaritonic Raman peaks, consistent with most experiments. In contrast, for a quasi-two-dimensional (2D) molecular layer, these rules are lifted, yielding Raman peaks at the polariton energies. Our Letter clarifies that the Raman response under vibrational strong coupling is determined by cavity-vibration spatial mode overlap and offers a framework for Raman studies of strongly coupled quasi-2D systems.

We consider the consequence of having nonreciprocal photon transfer between two surfaces with temperature gradient. We demonstrate that in a system consisting of graphene and a magneto-optical substrate separated by a gap, a transverse electric field is generated in graphene perpendicular to magnetic field and temperature gradient, in analogy to the Nernst effect. Such photon Nernst effect is driven by nonreciprocal Casimir force carried by photons. We show that the thermal efficiency of near-field photon Nernst effect is bounded by the Carnot limit, and nonreciprocal high-k modes are needed for approaching the limit. The near-field photon Nernst effect enables electrical probing of nonreciprocal radiative transfer and provides a novel means of energy harvesting.

Mean-field theories of the glass transition predict a phase transition to a dynamically arrested state, yet no such transition is observed in experiments or simulations of finite-dimensional systems. We resolve this long-standing discrepancy by incorporating critical dynamical fluctuations into a microscopic mode-coupling framework. We show that these fluctuations round off the mean-field singularity and restore ergodicity at all finite densities (or temperatures) without invoking activated dynamics or facilitation. The resulting effective theory describes the order parameter as a stochastic process with self-induced, annealed disorder, determined self-consistently at the mean-field level. In the $\beta$-relaxation regime it reduces to stochastic beta-relaxation theory, thereby unifying mode-coupling and replica-based approaches beyond mean field. All parameters of the stochastic beta-relaxation theory are fixed by the static structure, enabling parameter-free predictions that extend mean-field theory into finite dimensions.