We present a thorough study of spin-to-charge current interconversion in bulk and thin films of (0001) $\alpha \text{−}{\mathrm{Fe}}_2{\mathrm{O}}_3/\mathrm{Pt}$ heterostructures by means of all-optical polarization-controlled microwave excitation at subterahertz frequencies. Our results demonstrate that coherent spin pumping is generated through excitations of both the quasiferromagnetic and quasiantiferromagnetic (q-AFM) modes of antiferromagnetic resonance, provided that the corresponding selection rules are met for the relative orientation between the microwave magnetic field ${\overrightarrow{\mathit{h}}}_{\text{ac}}$ and the magnetic moment ${\overrightarrow{\mathit{m}}}_0$ of the hematite. In particular, our results unambiguously show that while a microwave field with ${\overrightarrow{\mathit{h}}}_{\text{ac}}\perp {\overrightarrow{\mathit{m}}}_0$ pumps a net spin angular momentum from the quasiferromagnetic mode, spin pumping from the q-AFM mode is only enabled when ${\overrightarrow{\mathit{h}}}_{\text{ac}}||{\overrightarrow{\mathit{m}}}_0$, as expected from the selection rules imposed by the Néel vector dynamics. Our findings significantly advance current understanding of spin pumping in easy-plane antiferromagnets not only by claiming a substantial contribution from the Néel-vector dynamics of the q-AFM mode but also by experimentally determining the relative strength of the intra- and cross-sublattice components of the spin-mixing conductance, challenging recent reports where the absence of spin pumping from the q-AFM mode in hematite was interpreted as a complete cancellation between these two components. We also provide an explanation for the previously reported observations and show how the q-AFM spin pumping actually vanishes for thin films, which we speculate being either due to an increased level of inhomogeneities or to insufficient film thickness for the q-AFM mode to fully realize.

Understanding stochastic gene transcription requires distinguishing between intrinsic molecular randomness and extrinsic environmental variability. Traditionally, these components are identified as the independent and correlated fluctuations between identical gene copies within the same cell. However, intrinsic gene-gene interactions can introduce additional correlations, challenging this standard approach. Here, we develop a new noise decomposition framework based on a theoretical model of stochastic transcription for an intrinsically coupled gene pair under fluctuating environments. By analytically deriving correlated fluctuations of nascent RNA, we disentangle intrinsic coupling from extrinsic noise based on their distinct relationships with the mean and variance of gene activation probabilities across varying environments. Applying this framework to single-cell transcription data from Drosophila embryos, we uncover previously unidentified couplings between sister alleles and between alternative promoters of an endogenous gene. Our findings offer a versatile approach for deciphering intrinsic gene-gene interactions in stochastic transcription within fluctuating environments.

Quantum computation offers significant potential for accelerating the simulation of molecules and materials through algorithms such as quantum phase estimation (QPE). However, the expected speedup in ground-state energy estimation depends critically on the ability to efficiently prepare an initial state with high overlap with the true ground state. For strongly correlated molecules such as iron-sulfur clusters, this overlap is demonstrated to decay exponentially with system size. To alleviate this problem, we introduce an efficient classical algorithm to find entanglement-minimized orbitals (EMOs) and their orderings using spin-adapted low-bond-dimension matrix product states (MPS). The EMO basis yields a more compact ground-state representation, significantly easing initial state preparation for challenging systems. Our algorithm improves initial state overlap by nearly an order of magnitude over prior orbital optimization approaches for an iron-sulfur cluster with four irons, and is scalable to larger systems with many unpaired electrons, including the P-cluster and FeMo-cofactor in nitrogenase with eight transition metal centers. For these systems, we achieve substantial enhancements on initial state overlap by factors of $\mathcal{O}({10}^2)$ and $\mathcal{O}({10}^5)$, respectively, compared to results obtained using localized orbitals. Our results show that initial state preparation for these challenging systems requires far fewer resources than prior estimates suggested.

The inclusion of spin effects in the binary dynamics for black holes and neutron stars is crucial for the computation of gravitational wave observables. Worldline supersymmetric models have been shown to be particularly efficient at this task up to quadratic order in spin, but progress at higher orders has been hampered by no-go theorems. In this Letter, we propose a novel approach to overcome this problem by extending the supersymmetry beyond minimal coupling. We demonstrate the potential of this approach by computing an “all-order-in-spin,” “linear in curvature,” manifestly supersymmetric Hamiltonian, as well as a “cubic-order-in-spin” Hamiltonian in arbitrary spacetime dimensions. In doing so, we identify a criterion that uniquely determines the Kerr geometry in terms of worldline supersymmetry. Equipped with these Hamiltonians, we demonstrate the exponentiation of three-point and Compton amplitudes using the recently proposed generalized Wilson line approach.

Transition-metal dichalcogenides exhibit multiple polymorphs that enable the exploration of diverse quantum states, including valley-selective spin polarization, the valley Hall effect, Ising superconductivity, and nontrivial topology. Monolayer $2H\text{−}{\text{NbSe}}_2$ is a promising candidate for realizing Ising superconductivity due to its spin-split, out-of-plane spin-polarized states arising from inversion symmetry breaking and strong spin-orbit coupling. In contrast, bulk $2H\text{−}{\text{NbSe}}_2$ retains inversion symmetry and lacks spin splitting, limiting its suitability for hosting Ising superconductivity. Here, we report the growth of high-quality single crystals of the acentric bulk superconducting polymorph $4H\text{−}{\text{NbSe}}_2$, which intrinsically breaks the inversion symmetry and supports valley-selective spin-polarized states. Magnetization and resistivity measurements reveal anisotropic superconductivity, with the in-plane upper critical field exceeding the Pauli limit, while out-of-plane fields suppress superconductivity more rapidly before reaching the Pauli limit, which strongly suggests the presence of Ising pairing. First-principles calculations and symmetry analysis confirm significant valley-selective spin splitting with out-of-plane spin polarization, further supporting the emergence of Ising superconductivity in $4H\text{−}{\text{NbSe}}_2$. These results establish $4H\text{−}{\text{NbSe}}_2$ as a robust bulk platform to investigate Ising superconductivity and valley-selective phenomena in transition-metal dichalcogenides.

We propose a modeling framework for binary-choice dynamics in which agents update their states using two mechanisms selected based on individual preference drawn from an arbitrary distribution. We compare annealed dynamics, where preferences change over time, and quenched dynamics, where they remain fixed. Our framework bridges gaps between existing models and provides a systematic approach to assess when individual-level diversity affects collective dynamics and when it can be effectively ignored. We identify a constraint on transition probabilities that makes annealed and quenched dynamics equivalent. We show that when this condition is satisfied, the quenched dynamics reduces to a one-dimensional system, ruling out oscillatory behavior that may otherwise emerge.

Avalanches are rapid cascades of rearrangements driven by cooperative flipping of hysteretic local elements. Here, we show that flipping dynamics and race conditions—where multiple elements become unstable simultaneously—give rise to dynamic avalanches that cannot be captured by static models of interacting elements. We realize dynamic avalanches in metamaterials with controlled flipping times and demonstrate how this allows us to modify, promote, and direct avalanche behavior. Our work elucidates the crucial role of internal dynamics in complex materials and introduces dynamic design principles for materializing targeted pathways and sequential functionalities.

Future mHz gravitational wave interferometers will precisely probe massive black hole environments, such as accretion disks, cold dark matter overdensities, and clouds of ultralight bosons, as long as we can accurately model the dephasing they induce on the waveform of extreme mass-ratio inspirals (EMRIs). Most existing models rely on extrapolations from Newtonian results to model the interaction of the small black hole in an EMRI system with the environment surrounding the massive black hole. Here, we present a fully relativistic formalism to model such interaction with collisionless environments, focusing on the case of cold dark matter overdensities, like “spikes” and “mounds.” We implement our new formalism in the fastemriwaveforms framework, and show that the resulting waveforms are significantly different from those based on a Newtonian treatment of environmental effects. Our results indicate that a fully relativistic treatment is essential to capture the environmental dephasing of gravitational wave signals from EMRIs accurately.

We study gravitational waves from a stellar-mass binary orbiting a spinning supermassive black hole, a system referred to as a binary extreme mass ratio inspiral (b-EMRI). We use Dixon’s formalism to describe the stellar-mass binary as a particle with internal structure, and keep terms up to quadrupole order to capture the generation of gravitational waves by the inner motion of the stellar-mass binary. The problem of emission and propagation of waves is treated from first principles using black hole perturbation theory. In the gravitational waveform at future null infinity, we identify for the first time Doppler shifts and beaming due to the motion of the center of mass, as well as helicity breaking gravitational lensing, and resonances with ringdown modes of the supermassive black hole. We establish that previously proposed phenomenological models inadequately capture these effects.

We present stationary and axially symmetric black hole solutions to the Einstein field equations sourced by an anisotropic fluid, describing rotating black holes embedded in astrophysical environments. We compute their physical properties, including quantities associated with the circular geodesics of massless and massive particles, analyze their shadows and image features, and analyze their energy conditions. Overall, we find that deviations from the Kerr metric grow with spin.

We define the “squared amplitudes” in planar Aharony-Bergman-Jafferis-Maldacena theory, analogous to those in $\mathcal{N}=4$ super-Yang-Mills (SYM) theory. Surprisingly, the $n$-point $L$-loop integrands with fixed $N≔n+L$ are unified in a single generating function. Similar to the SYM four-point half–Bogomol’nyi-Prasad-Sommerfield correlator integrand, the generating function enjoys a hidden $S_N$ permutation symmetry in the dual space, allowing us to write it as a linear combination of weight-3 planar $f$ graphs. Remarkably, through Gram identities it can also be represented as a linear combination of “bipartite” $f$ graphs that manifest the important property that no odd-multiplicity amplitude exists in the theory. The generating function and these properties are explicitly checked against squared amplitudes for all $n$ with $N=4$, 6, 8. By drawing analogies with SYM, we conjecture some “graphical rules” the generating function satisfies, and exploit them to bootstrap a unique $N=10$ result, which provides new results for $n=10$ squared tree amplitudes, as well as integrands for $(n,L)=(4,6),(6,4)$. Our results strongly suggest the existence of a “bipartite correlator” in Aharony-Bergman-Jafferis-Maldacena theory that unifies all squared amplitudes and satisfies physical constraints underlying these graphical rules.

We explore a general mechanism that allows $(1+1)\mathrm{d}$ CFTs to have interesting interface conformal manifolds even in the absence of any continuous internal symmetry or supersymmetry. This is made possible by the breaking of an enhanced continuous symmetry—which is generically noninvertible—arising in the folded theory. We provide several examples and showcase the power of the symmetry-based approach by computing the evolution of the reflection coefficient along the defect conformal manifold. We also discuss higher-dimensional generalizations and we comment on no-go theorems.

We report on a search for axion dark matter in the frequency range near 5.9 GHz, conducted using the haloscope technique. The experiment employed an 8-cell microwave resonator designed to extend the accessible frequency range by a multifold factor relative to conventional single-cell configurations, while maintaining a large detection volume. To enhance sensitivity, a flux-driven Josephson parametric amplifier operating near the quantum noise limit was utilized, together with a sideband-summing method that coherently combines mirrored spectral components generated by the Josephson parametric amplifier. Data were acquired over the frequency range 5.83–5.94 GHz. With no statistically significant excess observed, we exclude axion-photon couplings $g_{a\gamma \gamma }$ down to $1.2\times {10}^{-14}{\mathrm{GeV}}^{-1}$ at a 90% confidence level. The achieved sensitivity approaches the Kim-Shifman-Vainshtein-Zakharov benchmark prediction, setting the most stringent limits to date in this range.

The equation of state of deconfined strongly interacting matter at high densities remains an open question, with effects from quark pairing in the preferred color-flavor-locked (CFL) ground state possibly playing an important role. Recent studies suggest that at least large pairing gaps in the CFL phase are incompatible with current astrophysical observations of neutron stars. At the same time, it has recently been shown that in two-flavor quark matter, subleading corrections from pairing effects can be much larger than would be naïvely expected, even for comparatively small gaps. In the present Letter, we compute next-to-leading-order corrections to the pressure of quark matter in the CFL phase arising from the gap and the strong coupling constant, incorporating neutron-star equilibrium conditions and current state-of-the-art perturbative QCD results. We find that the corrections are again quite sizable, and they allow us to constrain the CFL gap in the quark energy spectrum to ${\mathrm{\Delta }}_{\mathrm{CFL}}\lesssim 140\mathrm{MeV}$ at a baryon chemical potential ${\mu }_{\mathrm{B}}=2.6\mathrm{GeV}$, even when allowing for a wide range of possible behaviors for the dependence of the gap on the chemical potential.