Excitons in two-dimensional semiconductors are directly exposed to the environment and are sensitive to the dielectric properties of their surrounding. Here, we show that the Rydberg series of excited states of excitons in a monolayer ${\mathrm{WSe}}_2$ encapsulated in hexagonal boron nitride (hBN) can be used to probe the pressure-induced modifications of the surrounding dielectric properties. We propose a model based on the pressure induced evolution of the interlayer distances in this van der Waals heterostructure and on the bulk dielectric properties of hBN. This approach allows a direct measurement of the dielectric constant of pressurized hBN and establishes a new methodology for dielectric sensing.

We experimentally study a system of $N=4$ two-dimensional Brownian particles, each confined in a harmonic trap with identical stiffness. The stiffness switches simultaneously between two values at random Poissonian times. This collective switching drives the system into a nonequilibrium stationary state with strong long-range correlations between the positions of the particles. Remarkably, we find that, despite the presence of hydrodynamic interactions between the particles mediated by the surrounding fluid, the statistics of some observables are insensitive to hydrodynamic interactions and are well described by the noninteracting theory. Comparing with exact theoretical predictions for noninteracting particles, we observe excellent agreement between theory and experiments for three such observables, namely, the correlations between particles, extreme value, and order statistics (maxima, minima, and ranked positions) and the full counting statistics (i.e., the distribution of the number of particles in a finite interval $[-L,L]$ around the trap center).

We establish a mapping between one-dimensional run-and-tumble particle dynamics in the presence of thermal noise, and overdamped Brownian motion in a spatially inhomogeneous temperature field. The approach is formulated as an inverse-Clausius thermodynamic framework, where the effective temperature is inferred from the steady-state density. Within this mapping, the local entropy flux and entropy production rate can be extracted directly from steady-state observables, without requiring explicit knowledge of the full position-velocity distribution. The framework introduces a closure that, to leading order, relates entropy flow to spatial variations of effective temperature, yielding a picture of entropy transfer from hotter to colder regions. We apply the approach to two-state and multistate run-and-tumble models in harmonic and nonlinear potentials. For harmonic confinement, the closure is exact in the two-state case and very accurate in multistate models. For nonlinear potentials that are locally confining (positive curvature at the origin), comparable accuracy is observed. In contrast, potentials with vanishing or negative curvature require higher-order corrections and reveal a correspondence between the spatial structure of the entropy production rate and that of the confining potential.

The interplay between external gauge fields and lattice geometry can induce extreme localization dynamics through complete destructive interference. We show that combining this flux-induced localization with engineered dissipation leads to robust spin synchronization in rotationally symmetric spin geometries, referred to as Aharonov-Bohm motifs, with cyclic symmetries of any order. The synchronized dynamics is independent of initial conditions and features entanglement among spins within each motif. We further demonstrate that multiple motifs can fully synchronize when coupled, which is achieved by applying additional collective dissipation acting on all intramotif spins. These results reveal a direct connection between flux-induced localization, dissipative engineering, and collective quantum synchronization.

Non-Markovian noise, arising from environmental memory effects, is the most general and challenging form of noise in quantum computing, and is typically difficult to characterize and suppress. Here, we analyze and experimentally demonstrate a non-Markovian noise suppression scheme inspired by quantum purification protocols. We theoretically prove that, even without noise calibration and assumptions on specific noise models, the scheme can exponentially reduce non-Markovian error rates with respect to the ancillary system size. We implement the protocol using nuclear spins, demonstrating that non-Markovian noise can be suppressed for both unitary operations and nonunitary channels. The observed fidelities and process tomography show close agreement with theoretical predictions, confirming the practicality and effectiveness of the scheme.

Extending the sensitivity of terrestrial gravitational-wave detectors below 20 Hz is a long-standing challenge, limited by ground motion and inertial sensing noise. In this Letter, we demonstrate ultra-high-vacuum compatible inertial isolation and position sensing technologies that achieve active platform stabilization down to 10 mHz. Our laser position sensors reach a $\mathrm{sub}\text{−}\mathrm{pm}/\sqrt{\mathrm{Hz}}$ sensitivity above 10 mHz, independent of the input light polarization, representing a 100-fold improvement over the current LIGO position sensors. In addition, our inertial sensors provide at least a factor of 5 improvement in low-frequency sensitivity compared to state-of-the-art commercial seismometers. We integrate these technologies into a LIGO-like interferometer model and predict a low-frequency sensitivity improvement of up to an order of magnitude at 10 Hz, with enhanced linearity and calibration stability. This extension increases the detection horizon for intermediate-mass black hole binaries of mass ${10}^3{M}_{\odot }$ by a factor of 3 and increases the SNR for all lower mass binaries. Our results provide the first experimental demonstration of a practical pathway to sub-10 Hz operation of terrestrial gravitational-wave detectors and establish key technologies for next-generation observatories such as Cosmic Explorer and Einstein Telescope.

IGR J17480-2446 is a low-mass x-ray binary, harboring an exceptional accreting pulsar (a neutron star) with an unusual spin frequency of 11 Hz and a very slow postoutburst crust cooling. The former may imply that it is observed at an early stage of recycling, while the latter was shown to indicate the presence in the outer crust of a low thermal conductivity layer, possibly made of glass. Here we argue that the glass layer formation is a natural result of accretion induced failure of pristine cold crystalline crust. This allows us to determine the mass of the accreted material as $\mathrm{\Delta }M\approx 2.4\times {10}^{-6}{M}_{\odot }$, confirming a very early accretion stage for this neutron star. An analysis of the spin and thermal state reveals a peculiar set of neutron star birth properties which is commonly associated with “recycled” neutron stars, i.e., those that have been experiencing prolonged periods of accretion from a companion. We speculate that such birth properties may represent the outcome of neutron star formation in an electron-capture supernova.

We show that the canonical formulation of the semiclassical Einstein equation, where the matter terms in the constraints are replaced by expectation values of the corresponding operators in quantum states, is inconsistent due to the nonclosure of the resulting constraint algebra.

Quantum noises impose limits on both backaction cooling and displacement measurements in macroscopic resonators. Here, we demonstrate that for dissipative optomechanical systems in the deeply unresolved sideband regime, squeezed-vacuum engineering of Fano interference enables broadband, tunable suppression of backaction noise and complete evasion of backaction heating, along with destructive noise correlations in the measurement spectrum. This leads to ground-state cooling over a cavity-linewidth scale for both blue- and red-detuned drives, as well as substandard quantum limit position sensitivity both at and away from mechanical resonance. Our Letter establishes squeezed-reservoir engineering as a powerful platform for exploring nonclassical correlations, quantum sensing, and information processing via noise-interference control.

Wave transmission reciprocity is broken by exploiting the synchronization of two coupled self-oscillators. The underlying principle is that illumination from one port drives the in phase, while illumination from the other port drives the antiphase synchronization state. Because of its self-adjustment the system is operationally stable. An experimental demonstration with aeroacoustic cavities is presented. They behave as weakly nonlinear limit cycles when driven by a constant airflow, leading to self-oscillations that can couple to the surrounding waveguides via two ports. Incident waves from one port trigger antiphase synchronization, causing destructive interference and low transmission, while waves from the opposite port induce in-phase synchronization, resulting in high transmission. This directional dependence effectively breaks reciprocity, where the operational bandwidth is defined by the synchronization region and can be broader than resonance-based methods. Experimental results show robust nonreciprocal behavior with respect to parameter changes. Moreover, a modified temporal coupled mode theory is proposed, explaining the system’s nonlinear dynamics and scattering properties in a quantitative manner. This synchronization-based approach offers a new avenue for directional wave control, complementing traditional reciprocity breaking techniques and offering an intrinsic loss compensation emanating from the self-oscillation of meta-atoms.

Recent X-point radiator (XPR) experiments in L-mode plasmas of the tungsten-W Environment in Steady-state Tokamak (WEST) tokamak show that a stable radiative ring can be sustained above the X point for approximately 70 s, on timescales not limited by intrinsic plasma physics, demonstrating the compatibility of the XPR regime with long-pulse operation and its ability to mitigate divertor heat loads and tungsten contamination while maintaining core performance. Accessing this regime in future reactors, however, requires understanding its rapid formation dynamics. Here, for the first time, time-dependent fluid simulations including magnetic drifts are used to investigate the macroscopic dynamics of the rapid transition from an attached divertor to a stable XPR regime, qualitatively reproducing the experimentally observed millisecond-scale transition sequence. The simulations identify a transient X-point-centered vortex as the key transition-driving mechanism. Arising from the self-organized interplay of anomalous diffusion and drifts, the vortex regulates the entry of cold particles and impurities into the XPR region, increases neutral density and impurity concentration above the X point without overcooling the edge, and thereby enables access to a stable XPR regime while preventing unstable XPR [known as The Multifaceted Asymmetric Radiation From the Edge (MARFE)]. By mixing cold and hot particles, steepening temperature gradients, and deepening the potential well, the vortex sustains a self-amplifying cycle over several milliseconds before saturating and decaying.

The emergence of the Abrikosov lattice in the normal phase of type-II superconducting films as the magnetic field approaches the critical field $H_{c2}$ from above was predicted in Glatz et al. [Fluctuation spectroscopy of disordered two-dimensional superconductors, Phys. Rev. B 84, 104510 (2011)]. In the quantum fluctuation regime [Galitski and Larkin, Superconducting fluctuations at low temperature, Phys. Rev. B 63, 174506 (2001)], it is characterized by the formation of relatively large (${\xi }_{\mathrm{QF}}\sim {\xi }_{\mathrm{BCS}}/\sqrt{\tilde{h}}$, $\tilde{h}=H/H_{c2}-1$) and long-lived (${\tau }_{\mathrm{QF}}\sim {\tau }_{\mathrm{\Delta }}/\tilde{h}$, ${\tau }_{\mathrm{\Delta }}=\hslash /\mathrm{\Delta }$) clusters of rotating fluctuation Cooper pairs, representing precursors of Abrikosov vortices. We show that these fluctuation-induced vortex clusters can be detected through their high-frequency electromagnetic response. Specifically, they produce a pronounced enhancement of the imaginary part of the ac conductivity at characteristic frequencies ${\omega }_{QF}\sim \tilde{h}/{\tau }_{\mathrm{\Delta }}$, arising directly from quantum fluctuations, being well below the superconducting threshold at $2/{\tau }_{\mathrm{\Delta }}$. For niobium, ${\omega }_{QF}$ falls within the experimentally accessible microwave range, making this effect directly testable using modern microwave spectroscopy.

Fluorite oxides, such as ${\mathrm{HfO}}_2$, exhibit rich and tunable phase behaviors, making them promising candidates for next-generation electronic devices. In this field, a key challenge consists in the design of amorphous ${\mathrm{HfO}}_2$-based high-$k$ materials with both structural and performance stability. Here, using molecular dynamics simulations supported by experimental measurements, we reveal that Ba doping stimulates a polyamorphic transition in ${\mathrm{HfO}}_2$, yielding a semiordered amorphous phase characterized by amorphized oxygens embedded within an ordered metal sublattice. We find that this phase arises from degenerate short-range symmetry breaking modes, consistent with Pauling’s parsimony rule. Notably, the semiordered amorphous structure is thermodynamically stable and displays a wider bandgap and higher dielectric constant than the conventional continuous-random-network amorphous structure, owing to suppressed subgap states and increased Born effective charges. We further demonstrate that this structural motif generalizes to Ba-, Sr-, and Ca-doped ${\mathrm{HfO}}_2$ and ${\mathrm{ZrO}}_2$, establishing a broadly applicable strategy for designing high-performance amorphous dielectrics.

The generation of exciton valley coherence typically requires linearly polarized (LP) light as an external coherent drive, whereas circularly polarized (CP) light fails to induce coherence. Here, we develop a unified, microscopically grounded open-quantum-system framework within a five-level model incorporating bright-dark exciton interactions in monolayer ${\mathrm{WSe}}_2$, and demonstrate that the polarization ellipticity of the excitation field provides selective control over distinct exciton species contributing to valley coherence. Specifically, LP and CP excitations generate bright and dark coherence, respectively, with continuous ellipticity tuning enabling controlled transitions between these states. We further reveal dual magnetic advantages for manipulating dark coherence even in the absence of initial coherence: (i) an out-of-plane magnetic field suppresses coherence decay and (ii) an in-plane field enables its optical readout, with quantitatively realistic field strengths. These findings provide a powerful mechanism for accessing hidden dark states via ellipticity-driven coherence transfer, and establish a new pathway for harnessing bright-dark valley-coherence transitions in future quantum control.

Midinfrared laser pulses tuned to optical phonon frequencies can induce magnetization switching in magnetic dielectrics, but the underlying mechanisms remain unclear, since excitations of the crystal lattice can simultaneously produce heating and nonthermal strain. Here, we study the response of labyrinthine magnetic domains in a cobalt-doped yttrium iron garnet film to midinfrared pulses. We observe a transformation of the labyrinthine domains into stable parallel stripes, which micromagnetic calculations can explain through a partial quenching of the magnetic anisotropy. Surprisingly, the efficiency of this thermally driven process of switching is spectrally strongest not at the maximum of absorbed optical energy, but rather at the epsilon-near-zero (ENZ) points. Electromagnetic calculations show that, in this regime, the optical field penetrates the film more uniformly, leading to homogeneous energy deposition across the magnetic layer. Our results demonstrate that magnetization switching can be controlled through engineering of the optical field distribution via the ENZ condition, which optimally shapes the spatial profile of optical absorption.

Device-independent (DI) certification allows the verification of quantum systems based solely on observed statistics, without assumptions about their internal structure. While self-testing, the strongest DI certification, of a wide range of quantum states and measurements is done, the self-testing of quantum operations remains underdeveloped. Here, we show in a proof-of-principle way that any quantum unitary can be self-tested within the DI paradigm. For our purpose, we utilize the framework of quantum networks with multiple independent sources. Our Letter provides a fundamental step toward certifying quantum interactions directly from data, without detailed modelling assumptions. Moreover, the result also serves as a crucial ingredient for quantum computation, where verifying that quantum gates perform as intended is essential for building secure and reliable quantum processors.