In dense colloids and simulated glasses, it has been discovered that plastic particle rearrangements correlate with nonphononic low-frequency vibrational modes. Here, we demonstrate that this correlation also holds for a very different material class of complex plasmas under shear, characterized by long-range interactions and nonreciprocal forces. We perform experiments with a deformed amorphous quasi-two-dimensional binary complex plasma under optical pressure, which gives rise to a controlled shear rate, and confirm our findings with extensive particle-resolved computer simulations.

Bulk-boundary correspondence is the foundational principle of topological physics, first established in the quantum Hall effect, where a $D$-dimensional topologically nontrivial bulk gives rise to ($D-1$)-dimensional boundary states. The advent of higher-order topology has generalized this principle to a hierarchical chain, enabling topological states to appear at ($D-2$) or even lower-dimensional boundaries. To date, all known realizations of topological systems must require a topologically nontrivial bulk to initiate the chain of action for bulk-boundary correspondence. Here, in an acoustic crystal platform, we experimentally demonstrate an exception to this paradigm—embedded topology in a trivial bulk—where the bulk-boundary correspondence originates from a trivial bulk. Rather than relying on global symmetries, we employ projective crystal symmetry, which induces nontrivial topology not at the outset in the $D$-dimensional bulk, but midway through the correspondence hierarchy in lower-dimensional boundaries. We further realize a three-dimensional system exhibiting embedded topology that supports zero-dimensional topological states, achieving the longest possible chain of action for such an unconventional bulk-boundary correspondence in physical space. Our Letter experimentally establishes a new form of bulk-boundary correspondence initiated from a trivial bulk, opening additional degrees of freedom for the design of robust topological devices.

In the last decade, the first law of binary black hole mechanics played an important unifying role in the gravitational two-body problem. More recently, binary black hole scattering and the application of high-energy physics methods have provided a new avenue into this classical problem. In this Letter, we connect these two themes by extending the first law to the case of scattering orbits. We present derivations based on classical S-matrix, Hamiltonian, and pseudo-Hamiltonian methods, the last of which allows us to include dissipative effects for the first time. Finally, a “boundary to bound” map links this first law to the traditional bound-orbit version. Through this map a little-known observable for scatter orbits, the elapsed proper time, is mapped to the Detweiler redshift for bound orbits, which is an invariant building block in gravitational waveform models.

We show that idealized Dicke superradiant decay from a fully inverted state can at all times be described by a positive statistical mixture of coherent spin states (CSS). Since CSS are separable, this implies that no entanglement is involved in Dicke decay. Based on this result, we introduce a new numerical quantum trajectory approach leading to low-entanglement unravelings. This opens up new possibilities for employing matrix product state (MPS) techniques for large-scale numerical simulations with collective decay processes.

Inelastic dark matter models that have two dark matter particles and a massive dark photon can reproduce the observed relic dark matter density without violating cosmological limits. The mass splitting between the two dark matter particles ${\chi }_1$ and ${\chi }_2$, with $m({\chi }_2)>m({\chi }_1)$, is induced by a dark Higgs field and a corresponding dark Higgs boson $h^{\prime }$. We present a search for dark matter in events with two vertices, at least one of which must be displaced from the interaction region, and missing energy. Using a $365{\mathrm{fb}}^{-1}$ data sample collected at Belle II, which operates at the SuperKEKB $e^{+}{e}^{-}$ collider, we observe no evidence for a signal. We set upper limits on the product of the production cross section $\sigma (e^{+}{e}^{-}\to h^{\prime }{\chi }_1{\chi }_2)$, and the product of branching fractions $\mathcal{B}({\chi }_2\to {\chi }_1{e}^{+}{e}^{-})\times \mathcal{B}(h^{\prime }\to x^{+}{x}^{-})$, where $x^{+}{x}^{-}$ indicates ${\mu }^{+}{\mu }^{-},{\pi }^{+}{\pi }^{-}$, or $K^{+}{K}^{-}$, as functions of $h^{\prime }$ mass and lifetime at the level of ${10}^{-1}\mathrm{fb}$. We set model-dependent upper limits on the dark Higgs mixing angle at the level of ${10}^{-5}$ and on the dark photon kinetic mixing parameter at the level of ${10}^{-3}$. This is the first search for dark Higgs bosons in association with inelastic dark matter.

Over the last few decades, the predominant strategies for controlling spontaneous emission have involved tailoring the spatial surroundings of quantum emitters or atoms to create resonant or spatially periodic photonic structures. However, the rise of time-varying photonics has prompted a reevaluation of spontaneous emission in dynamically changing environments, especially within photonic time crystals, where optical properties undergo time-periodic modulation. Here, we apply classical light-matter interaction theory together with Floquet analysis to reveal a substantial enhancement of the spontaneous emission decay rate at the momentum gap frequency in photonic time crystals. Moreover, our findings suggest that photonic time crystals enable a nonequilibrium light-matter interaction process: the spontaneous excitation of an atom from its ground state to an excited state, accompanied by the concurrent emission of a photon, referred to as spontaneous emission excitation.

Experimental and numerical studies of incompressible turbulence suggest that the mean dissipation rate of kinetic energy remains constant as the Reynolds number tends to infinity (or the nondimensional viscosity tends to zero). This anomalous behavior is central to many theories of high-Reynolds-number turbulence and has been termed the “zeroth law” for this reason. Here, we report a sequence of direct numerical simulations of incompressible Navier-Stokes in a box with periodic boundary conditions, which indicate the likelihood that the anomaly vanishes at a rate that agrees with the scaling of third moment of absolute velocity increments. Our results suggest that turbulence without solid boundaries or walls may not develop strong enough singularities to sustain the strict version of the zeroth law.

A novel approach designed to directly estimate microcanonical quantities from energy histograms is proposed, which enables the immediate systematic identification and classification of phase transitions in physical systems of any size by means of the recently introduced generalized microcanonical inflection-point analysis method. The application to the aggregation problem of GNNQQNY heptapeptides, for which the entire transition sequence is revealed, shows the power of this promising method.

We present the ultra-low-temperature thermal conductivity measurements on single crystals of the transition-metal dichalcogenide material $4{\mathrm{Hb}\text{−}\mathrm{TaS}}_2$, which has recently been proposed as a topological superconductor candidate. In zero field, a small residual linear term ${\kappa }_0/T$ is observed, indicating the existence of a residual density of states in the superconducting state. The slow field dependence of ${\kappa }_0/T$ at low fields rules out the presence of nodes in the superconducting gap, and the S-shaped field dependence across the full field range suggests multiple superconducting gaps in $4{\mathrm{Hb}\text{−}\mathrm{TaS}}_2$. Our results provide evidence for multiband gapless superconductivity in $4{\mathrm{Hb}\text{−}\mathrm{TaS}}_2$, and the residual density of states come from certain gapless Fermi surfaces.

The KM3NeT Collaboration recently announced the detection of a neutrino with energy 220 PeV. One possible source of such ultrahigh-energy particles is the rapid emission of energetic Hawking radiation from a primordial black hole (PBH) near the end of its evaporation lifetime. The mass distribution for PBHs features a power-law tail for small masses; a small subset of PBHs would be undergoing late-stage evaporation today. We find that recent high-energy neutrino events detected by the IceCube and KM3NeT Collaborations, with energies $\mathcal{O}(1-{10}^2)\mathrm{PeV}$, are consistent with event-rate expectations if a significant fraction of the dark matter consists of PBHs.

The annual modulation signal, claimed to be consistent with dark matter as observed by DAMA/LIBRA in a sodium-iodide based detector, has persisted for over two decades. COSINE-100 and ANAIS-112 were designed to test the claim directly using the same target material. COSINE-100, located at Yangyang Underground Laboratory in South Korea, and ANAIS-112, located at Canfranc Underground Laboratory in Spain, have been taking data since 2016 and 2017, respectively. Each experiment published its respective results independently. In this Letter, we present the results of an annual modulation search as a test of the signal observed by DAMA/LIBRA with the first three respective years of data from COSINE-100 and ANAIS-112. Using a Markov Chain Monte Carlo method, we find best fit values for modulation amplitude of $-0.0002\pm 0.0026\mathrm{cpd}/\mathrm{kg}/\mathrm{keV}$ in the 1–6 keV and $0.0021\pm 0.0028\mathrm{cpd}/\mathrm{kg}/\mathrm{keV}$ in the 2–6 keV energy regions. These results are not compatible with DAMA/LIBRA’s assertion for their observation of annual modulation at $3.7\sigma$ and $2.6\sigma$, respectively. Performing a simple combination of the newly released 6-year datasets from both experiments finds values consistent with no modulation at $0.0005\pm 0.0019\mathrm{cpd}/\mathrm{kg}/\mathrm{keV}$ in the 1–6 keV and $0.0027\pm 0.0021\mathrm{cpd}/\mathrm{kg}/\mathrm{keV}$ in the 2–6 keV energy regions with $4.7\sigma$ and $3.5\sigma$ respective exclusions of the DAMA/LIBRA signal.

The Event Horizon Telescope (EHT) has significantly advanced our ability to study black holes, achieving unprecedented spatial resolution and revealing horizon-scale structures. Notably, these observations feature a distinctive dark shadow—primarily arising from faint jet emissions—surrounded by a bright photon ring. Anticipated upgrades of the EHT promise substantial improvements in dynamic range, enabling deeper exploration of low-background regions, particularly the inner shadow defined by the lensed equatorial horizon. Our analysis shows that observations of these regions transform supermassive black holes into powerful probes for annihilating dark matter, which is expected to accumulate densely in their vicinity. By analyzing the black hole image morphology and performing electron-positron propagation calculations in realistic plasma backgrounds derived from general relativistic magnetohydrodynamic simulations, we set stringent constraints on dark matter annihilation, requiring contributions below the astrophysical emission. These constraints, derived from both current EHT observations and projections for future upgraded arrays, exclude a substantial region of previously unexplored parameter space and remain robust against astrophysical uncertainties, including black hole spin and plasma temperature variations.

Magnetic dynamics at the nanoscale provide crucial insight into the behavior of superconductors. Using single-spin scanning quantum microscopy, we probe vortex dynamics in the two-dimensional superconductor ${\mathrm{NbSe}}_2$. Our measurements reveal a disordered vortex glass phase that melts near the critical temperature and displays cooling-rate-dependent configurations. Surprisingly, magnetic noise persists well below $T_c$, with a strength that increases at lower temperatures—contrary to expectations. This behavior, detected via spin decoherence, points to an intrinsic origin driven by competition between supercurrent density and thermal fluctuations. Our results establish single-spin microscopy as a powerful platform for investigating fluctuations in 2D superconductors.

Interlayer sliding, together with twist angle, is a crucial parameter that defines the atomic registry and thus determines the properties of two-dimensional (2D) material homobilayers. Here, we theoretically demonstrate that controlled interlayer sliding in bilayer graphene induces Berry curvature reversals, leading to topological states confined within a one-dimensional moiré channel. We experimentally realize interlayer sliding by bending the bilayer graphene geometry across a nanoridge. Systematic electronic transport measurements reveal topological valley transport when the Fermi energy resides within the band gap, consistent with theoretical predictions of eight topological channels. Our findings establish interlayer sliding as a powerful tool for tuning the electronic properties of bilayer graphene and underscore its potential for broad application across 2D material systems.

We present the results of a first-principles theoretical study of the inclusive semileptonic decays of the $D_s$ meson. We performed a state-of-the-art lattice QCD calculation by taking into account all sources of systematic errors. A detailed discussion of our lattice calculation, demonstrating that inclusive semileptonic decays can nowadays be studied on the lattice at a phenomenologically relevant level of accuracy, is the subject of a companion paper [A. De Santis et al., Inclusive semileptonic decays of the $D_s$ meson: A first-principles lattice QCD calculation, Phys. Rev. D 112, 054503 (2025)]. Here, we focus on the phenomenological implications of our results. Using the current best estimates of the relevant Cabibbo-Kobayashi-Maskawa (CKM) matrix elements, our theoretical predictions for the decay rate and for the first two lepton-energy moments are in very good agreement with the corresponding experimental measurements. We also argue that, while the inclusive $D_s$ channel is not yet competitive with the exclusive channels in the $|V_{cs}|$ determination, the situation can be significantly improved in the near future.

Recent advances in laser excitation of the low-energy nuclear isomer transition in ${}^{229}\mathrm{Th}$ have opened avenues for developing nuclear clocks, a novel quantum technology with exceptional performance and sensitivity to exotic physics. Here, we explore the host dependence of the nuclear clock frequency, focusing on the isomer shift induced by the difference in the nuclear charge distribution between the ground and excited nuclear states. We combine relativistic many-body methods of atomic structure with periodic density functional theory to evaluate the isomer shifts in solid-state hosts. We elucidate the critical importance of the “relaxation” effect in evaluating the isomer shifts. Our analysis predicts nuclear clock frequencies for various solid-state and trapped ion platforms: ${\omega }_{\mathrm{clk}}(\text{solid state})=2020407384(40)\mathrm{MHz}$, ${\omega }_{\mathrm{clk}}({{}^{229}\mathrm{Th}}^{4+})=2020407648(70)\mathrm{MHz}$, and ${\omega }_{\mathrm{clk}}({{}^{229}\mathrm{Th}}^{3+})=2020407114(70)\mathrm{MHz}$. We also determine the nuclear transition energy for the bare ${}^{229}\mathrm{Th}$ nucleus to be ${\omega }_{\mathrm{nuc}}=8.272(22)\mathrm{eV}$. Our calculated valence band isomer shifts for different host materials constrain the nuclear transition frequencies to an 80-MHz-wide frequency window, aiding experimental searches for the ${}^{229}\mathrm{Th}$ nuclear transition in novel materials.

Semiconducting transition metal dichalcogenides are promising platforms for exploring emergent two-dimensional (2D) exciton physics and constructing 2D optoelectronic devices. However, even in mechanically exfoliated and hexagonal boron nitride encapsulated samples that are expected to maintain the most intrinsic properties, shallow defect states are still unavoidable. Here, we reported a method for eliminating the defect states in monolayer ${\mathrm{WSe}}_2$ by coupling it with a c-plane sapphire surface. We found that the defect-relevant photoluminescence peaks at cryogenic temperatures can be completely suppressed in ${\mathrm{WSe}}_2$ on c-plane sapphire, resulting in intrinsic exciton radiation, prolonged lifetime, and increased diffusion length. Ab initio calculations revealed that the surface of c-plane sapphire is much more active than other planes, where oxygen atoms preferentially transfer to ${\mathrm{WSe}}_2$ to repair selenium vacancy defects. Our Letter provides a new platform for defect engineering, which will promote the development of high-performance electronic and optoelectronic devices based on 2D materials.

Activation volume is a crucial concept in mechanochemistry because it describes how the applied mechanical energy facilitates chemical reactions. The activation volume can be determined readily from the load dependence of a chemical reaction based on the stress-assisted thermal activation theory (also known as the Bell model), but it is still very challenging to fully understand what activation volume means physically and how to compute it. Here, by introducing a concept of inherent stress difference (${\sigma }_{\mathrm{T}}$) between the initial and transition states, which is associated with the displacement of reacting atoms, a universal formula of activation volume ($\mathrm{\Delta }{V}^{*}$) for the interfacial reactions is derived, that is, $\mathrm{\Delta }{V}^{*}=(V_{\mathrm{eff}}{\sigma }_{\mathrm{T}}/E)$, where $E$ and $V_{\mathrm{eff}}$ refer to the Young’s modulus and the volume influenced by reaction, respectively. This formula implicates that $\mathrm{\Delta }{V}^{*}$ is related to the volume change from the initial to transition states. Then, the first-principles calculation was used to confirm the validity of the proposed definition in diverse types of chemical reactions. This Letter provides clear physical insight into how a chemical reaction that is unlikely to occur under thermal conditions is facilitated by mechanical stress, explaining the core principle of mechanochemistry.

Quantum defects in solids have emerged as a transformative platform for advancing quantum technologies. A key requirement for these applications is achieving high-fidelity single-spin readout, particularly at room temperature for quantum biosensing. Here, we demonstrate through ab initio simulations of a primary quantum defect in 4H silicon carbide that strain is an effective control parameter for significantly enhancing readout contrast. We validate this principle experimentally by inducing local strain in silicon carbide-on-insulator membranes, achieving a readout contrast exceeding 60% while preserving the favorable coherence properties of single spins. Our findings establish strain engineering as a powerful strategy for optimizing coherent spin-photon interfaces in PL6 divacancy centers within silicon carbide membranes and potentially other similar defect systems.

Observation of gamma rays from an exploding black hole would provide strong evidence for primordial black holes, the first direct evidence of Hawking radiation, and definitive information on the particles present in nature. However, indirect constraints suggest that direct observation of an exploding Schwarzschild black hole at current or upcoming gamma ray observatories is implausible. We introduce a dark-QED toy model consisting of a dark photon and a heavy dark electron. In this scenario a population of light primordial black holes charged under the dark $u(1)$ symmetry can become quasiextremal, so they survive much longer than if they were uncharged, before discharging and exhibiting a Schwarzschild-like final explosion. We show that the answer is “yes,” in this scenario the probability of observing an exploding black hole over the next 10 years could potentially be over 90%.