We present a comprehensive reassessment of perturbative unitarity bounds in the dimension-6 standard model effective field theory, exploiting a new formalism based on spinor-helicity techniques to derive partial-wave unitarity bounds for generic $N\to M$ scattering amplitudes. We find that, in several cases, these theoretical constraints are already competitive with, or even stronger than, the corresponding experimental bounds for energy scales above a few TeV. This is especially the case for four-fermion operators under realistic flavor assumptions, where unitarity bounds can be further strengthened by exploiting sum rules. These results provide a valuable and timely contribution toward the ambitious program of new-physics searches with minimal theoretical priors supplemented by restrictive, yet general, first-principles criteria.

Microelectromechanical—so-called “MEMs”—vapor cells are a key component in atom-based quantum sensors, such as clocks, gyroscopes, electric field sensors, and magnetometers. MEMs vapor cell fabrication for Rydberg atom radio frequency sensors is particularly demanding. The Rydberg states used for the sensor can shift in a constant electric field which can be generated by the internal surfaces of the vapor cell cavity. The ratio of the detection wavelength to vapor cell size can span a large range, meaning that the radio frequency field–vapor cell interaction is a critical design consideration. In many radio frequency sensing cases, there is a desire to minimize the interaction between the vapor cell and the target radio frequency field, as well as assure that every vapor cell behaves uniformly. These criteria favor MEMs vapor cells with low background electric fields. Known inert, organic coatings cannot survive the bonding temperatures required for conventional anodic bonding of a MEMs vapor cell. Applying inert, organic coatings to the internal cavities of MEMs vapor cells is a long-standing challenge. In this Letter, we present a low temperature bonding scheme that is compatible with coating the internal cavity of a MEMs vapor cell with octadecyltrichlorosilane [${\mathrm{CH}}_3({\mathrm{CH}}_2{)}_{17}{\mathrm{SiCl}}_3$, OTS]. The coating prevents the Cs used in the vapor cell from sticking to the walls. Spectral linewidths of $\sim 300\mathrm{kHz}$ are obtained using Rydberg spectroscopy, with energy shifts corresponding to electric fields $<10\mathrm{mV}{\mathrm{cm}}^{-1}$.

Droplet-laden cloud dynamics emerge from coupled phase transitions and turbulent mixing. Combining experiments and mean-field theory, we establish scaling laws for steam-injected clouds in unsaturated air seeded with condensation nuclei. Depending on whether the cloud is confined to the initial momentum-dominated zone of the jet or extends into the buoyancy-dominated plume, two asymptotic regimes arise. In the momentum regime, cloud dimensions scale with the injector radius. In the buoyancy regime, size follows a ${\dot{m}}^{2/5}$ scaling, where $\dot{m}$ is the injected steam mass flow rate. Assuming interdroplet air remains humidity saturated, our mean-field analysis predicts cloud persistence governed by enthalpy and humidity mixing. These findings bridge microphysical processes and macroscale dynamics, offering a quantitative framework for atmospheric cloud evolution.

Nonreciprocal charge transport, characterized by direction-dependent electrical response, provides a powerful probe of electronic structure and a platform for rectification. However, its realization is typically governed by intrinsic crystal symmetry, restricting the range of suitable materials. Here, we demonstrate nonreciprocal charge transport in an otherwise centrosymmetric superconductor, ${\mathrm{FeTe}}_{0.7}{\mathrm{Se}}_{0.3}$, through kink-boundary-induced strain engineering. The stress relaxation during growth generates a cusplike kink-band boundary with asymmetric curvature, producing a spatially nonuniform strain field and an effective in-plane polarity that breaks inversion symmetry. Pronounced nonreciprocal transport is observed under out-of-plane magnetic fields, with strong dependence on current and temperature across the superconducting transition, in contrast to the negligible response in flat nanosheets. Our results identify kink-boundary-induced symmetry breaking as a general route to engineer nonreciprocal charge transport in centrosymmetric systems.

Nanoscale hotspot thermal transport is critical for thermal management of electronic devices. Here, the thermal transport in nanoscale multiple hotspots is investigated by solving the phonon Boltzmann transport equation. To address the limitations of the conventional black-box treatment, a formal local thermal conductivity is proposed, which extends the classical framework to nanoscale nondiffusive regimes. The results reveal a highly nonuniform local thermal transport capability with up to a 13-fold variation across the system. A substantial heat flux deflection is also observed, which significantly deviates from the direction predicted by Fourier’s law. Furthermore, closely spaced nanoscale hotspots are found to enhance heat flux by up to 40%. This enhancement arises from a mechanism in which diffuse boundary scattering at hotspot spacing regions can enhance rather than impede thermal transport. This Letter challenges the long-standing black-box treatment of nanoscale thermal transport and offers fundamental insights for the thermal management of high-power-density integrated circuits.

Graphene, through the coexistence of large cyclotron gaps and small spin and valley gaps, offers the possibility to study the breakdown of the quantum Hall effect (QHE) across a wide range of energy scales. In this Letter, we investigate the breakdown of the QHE in high-mobility graphene Corbino devices under broadband excitation ranging from dc up to 10 GHz. We find that the conductance is consistently described by variable range hopping (VRH) and extract the hopping energies from both temperature- and field-driven measurements. Using VRH thermometry, we can distinguish between non-Ohmic and Ohmic regimes of bulk conduction, which are dominated by electric-field-assisted VRH and Joule heating, respectively. Our results demonstrate that the breakdown in the quantum Hall regime of graphene is governed by a crossover from non-Ohmic, field-driven VRH to Ohmic, Joule-heating-dominated transport.

Intelligent behavior in lifelike systems often arises from the ability to gather, process, and act on information. While active matter provides a framework for studying lifelike dynamics, it typically omits internal information processing and decision making. Here we introduce an adaptive active particle model that uses minimal information processing capabilities in order to navigate toward a distant target. By combining renewal-based intermittent motion with the Cramér-Rao inequality, we derive a bound on the navigation speed valid for a wide range of information processing strategies. The framework captures hallmark features of cognitive systems, including optimal sensing durations and a trade-off that balances noise and reliability. Allowing stored information to degrade before action reveals that, although deterioration slows navigation, the trade-off remains governed primarily by external orientational noise and is remarkably insensitive to memory decay.

We extend the classical test particle insertion (TPI) method to anisotropic systems and develop an anisotropic test particle insertion (ATPI) framework that efficiently extracts anisotropic interaction potentials from dense fluids using a small number of equilibrium snapshots. The method leverages the parallelizability of the insertion process, enabling rapid reconstruction of complex anisotropic interactions via high-performance computing. The ATPI method is quantitatively validated for liquids in both simulations and colloidal experiments. With a few modifications, this method is able to extract anisotropic interactions from solid lattices. By exploiting the theoretical equivalence between interaction measurement and design, we further demonstrate that ATPI can be used to construct interaction potentials that drive the system into target structures such as honeycomb lattices, kagome lattices, and dodecagonal quasicrystals. Our approach opens a new avenue for the inverse design of self-assembling systems.

The Motzkin spin chain is a well-known mathematical model with connections to symmetry-protected topological phases, such as the Haldane phase, as well as to concepts in the AdS/CFT correspondence. They exhibit highly entangled ground states that violate the area law and are exceptionally difficult to simulate with conventional numerical methods. Numerical simulations of the Motzkin ground state become further challenging at large system sizes due to their high-dimensional spin structure, rendering it a natural test bed for quantum simulation with ultracold systems. Here, we propose a Rydberg-atom based quantum simulation scheme that effectively realizes Motzkin spins using an experimentally accessible set of parameters. We show that the resulting effective Motzkin ground state reproduces the characteristic entanglement scaling and the block-structure properties of the reduced density matrix associated with the ideal Motzkin state. Our results establish a pathway toward a concrete experimental realization of Motzkin spins beyond purely mathematical constructions, opening avenues for exploring other similar exotic non-area-law entangled phases in programmable Rydberg simulators.

Correlated noise naturally arises in quantum systems due to, e.g., phase and amplitude fluctuations in global control or long-range correlations generated by a many-body sensing target near criticality. In this Letter, we propose a new form of exponential quantum advantage in the context of sensing correlated noise. Specifically, we focus on the problem of estimating parameters associated with Lindblad dephasing dynamics, and show that entanglement enhancement in the sensitivity (as quantified via quantum Fisher information of the sensor state) arises for estimating the strength of fluctuations in the noise fields’ center-of-mass mode. In the presence of strong background fluctuations, such enhancement grows exponentially with the number of probes in the shot-limited regime, where the measurement and reset operations are slow. This result stands in stark contrast with previously studied scenarios of sensing uncorrelated dephasing noise, where one can prove that entanglement does not lead to an advantage in the signal-to-noise ratio. Our Letter thus opens a novel pathway toward achieving entanglement-based sensing advantage, which may find applications in characterizing decoherence dynamics of near-term quantum devices. Further, our approach provides a potential quantum-enhanced probe of many-body correlated phases by measuring noise generated by a sensing target. We also discuss realization of our protocol using near-term quantum hardware.

We explore the phase diagram of a lattice fermion model that exhibits three distinct phases: a massless fermion phase, a massive fermion phase with spontaneous symmetry breaking induced by a fermion bilinear condensate, and a massive fermion phase with symmetric mass generation. Using the fermion-bag Monte Carlo method on large cubical lattices, we find evidence for traditional second-order critical points separating the first two and the latter two phases. Remarkably, these critical points appear to merge at a multicritical point with enhanced symmetry when the symmetry breaking parameter is tuned to zero, giving rise to the recently discovered direct second-order transition between the massless and symmetric massive fermion phases.

We report the observation of a kinetic-energy-release feature at 3.8 eV in the dissociative double ionization of NO dimers driven by intense femtosecond laser fields. This channel is separated from the 5.6 eV signature of direct Coulomb explosion and is absent under electron-impact ionization. Ab initio electronic-structure calculations identify the low-energy feature as arising from intermolecular Coulombic decay initiated by strong-field-induced coupling between the ${\mathrm{NO}}^{+}(1{{}^1\mathrm{\Sigma }}^{+})-\mathrm{NO}(\mathrm{X}{}^2\mathrm{\Pi })$ ground configuration and an excited ${\mathrm{NO}}^{+}(2{}^1\mathrm{\Pi })-\mathrm{NO}(\mathrm{X}{}^2\mathrm{\Pi })$ state, followed by nonlocal relaxation to the ${\mathrm{NO}}^{+}(1{{}^1\mathrm{\Sigma }}^{+})-{\mathrm{NO}}^{+}(1{{}^1\mathrm{\Sigma }}^{+})$ state at enlarged intermolecular separations. This coupling is resonantly enhanced in a two-color field formed by the spatiotemporal overlap of 800 and 400 nm femtosecond pulses, resulting in a pronounced increase of the intermolecular Coulombic decay yield. These findings demonstrate that femtosecond laser excitation can initiate intermolecular Coulombic decay in NO dimers through strong-field population of an electronically excited doorway state.

The melting temperature of elemental bismuth under high pressure has been measured to 55 GPa using synchrotron x-ray phase-contrast imaging in the laser-heated diamond anvil cell. Imaging of solid-liquid interface formation, combined with radiometric temperature and x-ray diffraction measurements, reveals a pronounced reduction in melting boundary slope in Bi-V with pressure. The unusually steep initial slope is attributed to low configurational entropy of melting, arising from structural ordering and coordination matching in the cool liquid, while slope reduction is driven by entropy increase correlated with significant liquid structure changes with rising pressure and temperature. The data rule out kinetic effects on melting in shock compression experiments and demonstrate the need for improved theoretical phase diagrams.

The GW approximation accurately describes single-particle excitations but is typically limited by high computational complexity and a large prefactor. We develop a low-rank strategy by combining the interpolative separable density fitting method with the Sherman-Morrison-Woodbury formula to efficiently implement GW-family calculations in different approximation frameworks. Our method resolves the bottlenecks of four-center integrals and screened Coulomb interactions in GW calculations, achieving cubic scaling with a small prefactor and delivering over $50\times$ speedup compared to the berkeleygw implementation within the COHSEX approximation. We perform a GW calculation for a lithium-hydrogen system with 10 648 atoms on a single compute node, demonstrating the feasibility of excited-state simulations for large-scale systems using limited computational resources.

Heavy-fermion metals are prototype correlated electron systems for the study of Kondo entanglement and quantum criticality. We use the symmetry decomposed elastoresistance to uncover the fingerprints of strain-dependent Kondo scattering as a function of temperature and magnetic field in the prototypical tetragonal Kondo lattice ${\mathrm{YbRh}}_2{\mathrm{Si}}_2$. By combining longitudinal and transverse resistance measurements under uniaxial strain applied along the tetragonal [100] and [110] directions, we obtain the elastoresistive responses in the in plane $A_{1g}$, $B_{1g}$, and $B_{2g}$ symmetry channels. While the responses in the symmetry-breaking channels are negligible, a huge enhancement of the isotropic symmetric $A_{1g}$ elastoresistance is found approaching $-50$ at low temperatures. Scaling analysis and comparison with linear thermal expansion measurements reveal that the symmetric elastoresistance probes the contribution of Kondo scattering to the strain dependence of magnetic entropy and signals strain- and field controlled quantum criticality upon cooling to 2 K.

Entangled states of photons form the foundation of quantum communication, computation, and metrology. Yet their generation remains fundamentally constrained: in the absence of intrinsic photon-photon interactions, the generation of such states is inherently probabilistic rather than deterministic. The prevalent technique of postselection verifies the creation of an entangled state by detecting and thus destroying it. Heralding offers a solution in which measuring ancillary photons in auxiliary modes signals the state generation without the need to measure it. Here, we introduce and experimentally demonstrate a scheme to generate a three-mode NOON state, where the detection of a single photon in one heralding mode signifies the presence of the state in three target modes. We validate the generated state by estimating a fidelity of $0.823\pm 0.018$ with respect to an ideal three-mode NOON state and certifying genuine multipartite entanglement. By virtue of the high success probability and small resource overhead of our scheme, our Letter provides a theoretical and experimental stepping stone for entangled multimode state generation, which is realizable with current technology. These multimode entangled states represent a key direction for linear optical quantum information that is complementary to multiqubit state encoding.