Papers

We study the transport properties of proximitized graphene, which can acquire a spin-orbit coupling by the proximity effect with a substrate. We focus on the ballistic and zero temperature limits, making use of a tight-binding procedure based on the KWANT Python package. We first find key results on valley-filtering properties and asymmetric edge transport in spin-orbit coupled graphene single junctions, and then move to the analysis of the superconducting transport in a graphene Josephson junction, in the short junction limit. We study the relative contribution of edge modes for different edge terminations and some degree of edge disorder, and also analyze the magnetic interference pattern that arises when threading the junction with a perpendicular magnetic field. We find residual supercurrent at high magnetic fluxes, due to the localized nature of transport in the junction, and a strong non-reciprocal transport that leads to a significant Josephson diode effect.

We present a systematic imaging and spatially resolved spectral study of SN 1987A using Chandra observations obtained between 1999 and 2025. By combining multiepoch ACIS and HETG data, we investigate the long-term evolution of the remnant in both the soft and hard X-ray bands. To characterize the radial structure, we model the projected emission with a torus profile and derive its radius and width on the image plane. We find an energy dependence in the ring morphology: while the soft and hard bands exhibit similar structures at early epochs, the soft-band emission becomes systematically broader than the hard-band emission after the early 2010s. Furthermore, when considering the radius and width together, the soft-band emission shows an inward extension, suggesting an increasing contribution from interior and/or high-latitude emission components. The flux evolution of the Fe K line is consistent with previous XMM-Newton results, and we detect its presence already in earlier epochs (~2007-2009) using combined Chandra spectra. Spatially resolved analysis further indicates that the Fe K emission is enhanced in the eastern region. These results provide a unified view of the long-term morphological and spectral evolution of SN 1987A and highlight the emergence of energy-dependent radial structure as a key feature in its late-time evolution.

We investigate how cavity-mediated attractive electron-electron interactions modify the excitation gaps of fractional quantum Hall states within the composite-fermion framework. We compute both the neutral magnetoroton excitation spectrum and the charged excitation gap relevant to transport experiments for the Laughlin $\nu=1/3$ and $\nu=1/5$ states. We consider a spin-polarized lowest-Landau-level model in which the interaction is mediated by a cavity mode with a spatially uniform vacuum-field gradient and a finite interaction range controlled by a long-distance cutoff. Finite-size scaling reveals that the transport gap is consistently enhanced by the cavity-induced interaction, with the gap enhancement scaling quadratically with the electron number and with the fourth power of the vacuum-field gradient. By contrast, the magnetoroton spectrum exhibits a richer dependence on the interaction range. The high-$k$ magnetoroton gap is enhanced for all interaction ranges considered, consistent with its close connection to the charged excitation gap, even with the long-range character of the interaction.

We introduce a mapping between the ground state of interacting fermionic Hamiltonians and the non-equilibrium steady state of a purely dissipative open quantum system. Within the framework of third quantization, we map the Fermi-Hubbard Hamiltonian onto Lindblad jump operators acting on Majorana fermions. Remarkably, both hopping and interaction terms map onto jump operators that preserve the Gaussianity of Majorana fermions along individual quantum trajectories. As a result, the dynamics can be unravelled and each trajectory can be simulated efficiently using only two-point correlation functions, with a computational cost that scales polynomially with system size. We further show that finite particle number requires negative dissipative rates, leading to an intrinsically non-Markovian dynamics. The corresponding trajectory unravelling involves both positive and negative stochastic weights and exhibits a sign problem and large fluctuations, so that convergence requires an exponentially large number of trajectories. The overall computational cost remains exponential in system size despite the efficient Gaussian representation of individual trajectories, but is crucially dependent on the computational complexity of the non-Markovian unravelling, motivating further studies on the efficiency of such unravellings.

We nonperturbatively compute Rényi entropies for strip-shaped subregions in the three-dimensional O(4) model at finite density on the lattice. By using a dual variable representation and a tailored worm algorithm, we circumvent the sign problem when sampling the grand canonical ensemble. In the limit of large subregions, we also establish a direct, quantitative relationship between the derivative of entanglement entropy with respect to the size of the entangling region and the thermal entropy density for general quantum field theories, providing a new way to study their thermodynamics. We corroborate this argument with our lattice results by demonstrating that, in the appropriate limit, the derivative of entanglement entropy satisfies the same Maxwell relation as the thermal entropy density.

Braiding statistics of $p$- and $q$-dimensional topological excitations is conventionally defined in $p+q+2$ spatial dimensions. We find a novel statistical process $W_N(X,Y)=(Y^{-1}X^{-1})^N(YX)^N$ for two order-$N$ excitations in $p+q+1$ dimensions, detecting the Bockstein response $A\smile \beta(B)$. This new statistics and fermionic loop statistics exhaust all loop statistics in three dimensions whose fusion rules form an Abelian group $G$, classified by $H^5(B^2G,U(1))$. Surprisingly, conventional three-loop braiding goes beyond this classification, so it must have non-Abelian fusion rules. We suggest viewing three-loop braiding as particle-loop braiding together with exotic fusion rules between loops and point-like defects. We also try to clarify the relationship between statistics and symmetry anomaly.

Spin-photon interfaces based on silicon quantum emitters offer a scalable platform for quantum computing and networking. However, achieving coherent photon emission remains a primary challenge due to stringent material quality requirements. To overcome this, we utilise high-purity molecular-beam epitaxy (MBE) to epitaxially incorporate single T centres in silicon-on-insulator (SOI) wafers. We demonstrate single T-centre emission coupled to a nanophotonic waveguide and observe significant suppression of homogeneous broadening, yielding optical linewidths as narrow as 30 MHz using natural silicon for crystal growth. These results establish epitaxial T centres as a robust foundation for coherent spin-photon interfaces in silicon quantum photonics.

Synthetic quantum matter provides a highly tunable route to fractional quantum Hall physics beyond the constraints of conventional electronic materials. However, previous theoretical studies have mostly focused on their ground state properties. It remains unclear to what extent such platforms could reveal key excitation properties of fractional quantum Hall states. Here, we study charge-neutral collective excitations in a non-abelian lattice fractional quantum Hall state realized in the bosonic Harper-Hofstadter model at unity filling factior, realizing a Moore-Read ground state. Combining full exact diagonalization, band-projected exact diagonalization, and matrix-product-state simulations, we demonstrate the existence of a long-lived chiral graviton mode, probed by chiral 3-body correlators, for the first time on lattice non-Abelian states. The graviton signal is topological sector-independent and could be observed via geometric quenches in small open droplets directly relevant to current cold-atom experiments, while other neutral modes, such as the magnetoroton and neutral fermion, are less resolved at presently achievable volumes.

Similarly to Thomson, we consider the thermoelectric generator at open circuit as a classical heat engine. It is shown that, as long as the Thomson coefficient is nonzero, the operation generates entropy and is therefore irreversible. By expanding Thomson's approach we show that the voltage produced can be described by the usual Guy–Stodola equation for classical heat engines.

Ferroelectric nematic liquid crystals (FNLCs) are polar fluids in which spontaneous polarization coexists with nematic orientational order, giving rise to unusual dielectric and electromechanical responses. However, the collective modes underlying their giant dielectric response remain unclear. Here, we show that this response originates from the superposition of two distinct relaxation modes rather than a single process. Dielectric spectroscopy reveals that the low-frequency mode exhibits soft-mode-like behavior associated with short-axis molecular rotation, whereas the high-frequency mode corresponds to a Goldstone-like phase displacement of an effective transverse polarization component rotating around the director. These assignments are supported by systematic analyses of temperature, electric-field, cell-thickness, and alignment-layer dependences. Our results demonstrate that the giant dielectric response of ferroelectric nematics reflects multiple collective polarization dynamics with different symmetries and restoring forces, providing a framework for interpreting dielectric spectra in polar nematic fluids.

We study the $J/\psi \to \bar{\Lambda} \Lambda \pi^0$ reaction, an isospin violating reaction, by looking at the trios of baryon-antibaryon-pseudoscalar meson that conform a singlet of $\text{SU}(3)$ in the $u, d, s$ quarks. These terms conserve isospin; however, once the final-state interactions of meson-baryon and meson-antibaryon are taken into account, isospin is violated due to the different masses of particles within the same isospin multiplets. Since the reaction is tied to the interaction of particles, only resonances that are dynamically generated by these interactions show up in the reaction. In this sense, our approach produces the $\Sigma(1430)(1/2^-)$ state, but not the $\Sigma(1385)(3/2^+)$. Comparing with the BESIII data we observe that, within the limited statistics of the experiment, the data show a structure {around $M_{\pi\Lambda} = 1430$ MeV} that is reproduced by the theory, and no signal is seen for the $\Sigma(1385)(3/2^+)$ as the theory predicts. We call for a future update of the experiment once better statistics become available.

Conventionally, the local spin magnetization in itinerant magnets is determined from the equilibrium local spin density. Here, we propose a thermodynamic approach in which the local spin magnetization is defined from the response of the system to an infinitesimal external magnetic field. The predictions of the two theories are identical for collinear magnets, but differ qualitatively and quantitatively for non-collinear magnets. In the present thermodynamic approach, the spin coherences determine an alternative distribution of local spin magnetization due to the field-induced deformation of the energy eigenstates. This effect is captured by a Berry-curvature-like contribution reminiscent of orbital magnetization and has several distinct observable consequences. We explore the differences between the conventional and thermodynamic approaches in several test cases.

We provide a resolution to the non-Abelian Rainich problem. By canonically identifying traceless symmetric $(0,2)$-tensors with Hermitian forms on the vector bundle of chiral 2-forms, we define the internal square roots of a stress-energy tensor. We then prove that the existence of a local $\operatorname{SU}(2)$ Yang-Mills field with prescribed stress-energy tensor $T$ is equivalent to a single differential condition on internal square roots of $T$.

The vertical structure of Jupiter's jet streams remains a critical open question for understanding the planet's atmospheric dynamics and interior. Traditional models often assume an adiabatic density profile, yet recent observations and theory suggest the presence of stable layers, which could significantly alter both the density structure and gravitational signature. We investigate the implications of non-adiabatic stable layers for Jupiter's gravity field, focusing on how density anomalies from such layers interact with the inferred vertical structure of zonal winds. We construct temperature-pressure profiles including subadiabatic stable layers to derive density profiles consistent with the latest equation of state. The resulting gravitational harmonics are computed, incorporating both static density and wind structure via thermal wind balance, and compared with Juno measurements. By varying the wind decay characteristics, we assess how stable layers constrain the depth and structure of the deep jets. Our results show that shallow, extensive stable layers substantially modify the background density, requiring more rapid decay of zonal winds to satisfy observed gravitational constraints. Introducing stable layers also broadens the range of physically plausible wind solutions, inadicating that the vertical structure of the jets is less constrained than suggested by purely adiabatic models. We conclude that stable layers are a critical, yet often overlooked, component in modeling Jupiter's interior and dynamics. This study highlights a strong degeneracy between the thermodynamic density structure and the vertical wind profile, implying that the jet stream structure cannot be uniquely determined without independent constraints on the planet's internal stability.

Pulse-echo speed-of-sound (SoS) imaging based on minute misalignments between consecutively acquired ultrasound images traditionally relies on images beamformed on Cartesian grids. Existing SoS imaging developments do not allow for real-time imaging and typically do not prioritize feasibility in conventional ultrasound systems that have limited resources and rigid processing structures. In this work, we propose a resource-efficient approach based on radial beamforming with virtual source transmits for implementation within an on-the-fly beamformer. We also introduce alternating transmissions with fast pair-alternating beamforming for motion-robust displacement tracking with typical line-based beamformers. We tested these methods comparatively on numerical simulations, tissue-mimicking phantom experiments, and in vivo data from breast lesion examinations. We demonstrate that the proposed radial grid beamforming approach performs comparably to a Cartesian grid approach, while allowing implementation on standard hardware for beamforming. Our proposed sequences would allow for SoS data acquisition frame rates of more than 20 fps in parallel to conventional B-mode imaging. The proposed speckle-shift based radial approach with fast alternation between congruent beamforming lines is a major step towards real-time SoS imaging on standard ultrasound systems with moderate resources.

Photonic integrated circuits (PICs) enable optical systems with dramatically increased performance, cost-effectiveness, and scalability through enhanced light-matter interactions, high-density integration, and mass production. Due to the significant mode mismatch between various integrated photonic platforms and optical fibers, spot-size conversion interfaces with low-loss, compact footprint, and high manufacturability are essential. Conventional spot-size converters based on intuitive designs often require multi-layer tapering structures and tiny waveguide tips to adiabatically expand the eigenmodes. These rigid design constraints commonly lead to large device footprints and the requirements of multiple high-precision lithography steps. In this paper, we overcome these limitations using inverse design methods, which optimize the coupling efficiency over a large parameter space beyond traditional eigenmode evolution limits. Specifically, we demonstrate efficient and ultra-compact photonic interfaces on the thin-film lithium niobate (TFLN) platform, where the partially etched rib waveguides and non-vertical sidewalls have previously hindered the achievement of low-loss waveguide tapers in single-layer configurations. Our inverse-designed photonic structures achieve simulated and experimentally measured coupling efficiencies as low as 1 dB and 3 dB per facet between TFLN waveguides and lensed/ultra-high numerical aperture (UHNA) fiber, with broad 1-dB bandwidths exceeding 120 nm. The inverse-designed interfaces are highly compatible with standard TFLN PIC components and require only a single high-resolution lithography step. More importantly, the design concept transcends traditional eigenmode evolution theories and is broadly applicable to a variety of material platforms and application scenarios.

In this work, we analyze the flux-integrated inclusive and pionless differential cross sections for neutrino scattering off argon. The cross sections are calculated using the relativistic distorted-wave impulse approximation (RDWIA), taking into account the contribution of the two-particle-two-hole (2p-2h) meson-exchange currents (MEC). We find that the measured single- and double-differential cross sections can be well described within the experimental uncertainties using this approach. We also compare the differential cross sections for pionless neutrino scattering on carbon and argon, measured with the Booster Neutrino Beam flux in the MiniBooNE and MicroBooNE experiments, to study nuclear effects in these nuclei.

Twistor theory forms the basis for many surprising advances in areas ranging from dynamical systems to quantum field theory. Yet for almost fifty years, one of the main drawbacks of twistor theory has been its inability to give non-perturbative descriptions of non-chiral (or non-self-dual) field configurations. This difficulty is known as `the googly problem.' In this paper, we provide a resolution of the googly problem for a particular solution of the vacuum Einstein equations: the Schwarzschild metric. We start with the twistor space of the self-dual Taub-NUT Euclidean gravitational instanton, expressed in Kerr-Schild form. Within this twistor space, we then consider a quadric which corresponds to the anti-self-dual Taub-NUT metric. While the full quadric is not holomorphic with respect to the complex structure of the self-dual Taub-NUT twistor space, its holomorphic locus still has complex dimension two. This `coincidence locus' – points in twistor space on the holomorphic portion of the quadric – inherits a complex structure from the twistor space and a symplectic form from the quadric itself. Remarkably, these structures are compatible, giving rise to a non-self-dual, four-dimensional Kähler metric which is conformal to Schwarzschild (in Lorentzian or Euclidean signature). This is the first instance of a non-self-dual Einstein metric constructed entirely from holomorphic data in a twistor space.

Wigner function learning is a central tool for characterizing continuous variable quantum systems. A fundamental challenge in this setting is to infer a continuous phase-space function from sparse pointwise measurement data, a task that becomes increasingly demanding as the effective dimension enlarges. Here, we develop a general machine learning framework to reconstruct Wigner functions directly as continuous functions from sparse phase-space data. For states with sparse Fock-space or coherent-state representations, such as binomial code states and cat states, we devise provably efficient regression models whose measurement complexity scales only logarithmically with the effective Hilbert-space dimension. For more general states, such as the Gottesman-Kitaev-Preskill (GKP) states, we design a deep learning model that reconstructs the Wigner function from sparse measurements and generalizes to arbitrary phase-space resolution. We demonstrate the broad applicability of our framework on both simulated data and experimental data from a circuit quantum electrodynamic (circuit-QED) system. Interestingly, on experimental data, we find that our model reconstructs Wigner functions of GKP code states across multiple rounds of quantum error correction and identifies the dominant error process using significantly fewer measurements than conventional estimation techniques.

Parameterized quantum circuits (PQCs) are increasingly used as policies and value functions in quantum reinforcement learning, yet it remains unclear when and why quantum policies generalize. We give a PAC-Bayesian account in which generalization is governed not by the raw number of circuit parameters, but by the effective dimension of the Fisher geometry induced by the circuit. This quantity is inflated by entanglement, making entangling connectivity an independent axis of complexity.In controlled experiments that fix the number of trainable rotations and vary only entanglement, we find that circuits with larger Fisher effective dimension exhibit larger train-test gaps, while parameter count is a weak predictor. The resulting bound acts primarily as a ranking certificate: it correctly orders circuits with identical parameter count, which parameter-counting bounds cannot do. We validate this mechanism across supervised classification, quantum contextual bandits, and value-function generalization, where entangled circuits consistently generalize worse than non-entangled circuits of equal parameter count, with gaps shrinking as sample size increases.Our strongest evidence comes from low-variance decision models, including single-observable classifiers, value heads, and one-step policies. In end-to-end multi-step policy learning, entanglement effects remain statistically significant but high return variance leaves the full ordering only partially resolved. Partial-correlation analysis shows that Fisher effective dimension screens off entangling pattern, and controls for training accuracy, readout, and optimizer rule out major optimization confounders. The effect also persists on an IBM Heron quantum processor under real noise. Overall, our results reframe quantum policy design around an entanglement–generalization trade-off rather than expressivity alone.

Inverse Compton X-ray sources are laboratory-scale devices providing quasi-monochromatic synchrotron radiation which is generated by laser photons Compton-scattering off highly relativistic electrons. Since the shape and width of the X-ray spectrum are determined by the properties of the colliding beams, these must be carefully optimised. However, device compactness limits the space for diagnostics, rendering a complete characterisation challenging, especially if an electron storage ring is combined with a laser enhancement cavity. Here, a framework for laser, electron and X-ray beam parameter determination is proposed to address this issue. First, methods for determining the laser- and X-ray parameters are presented. Knowing these, electron beam parameters are retrieved from the shape of the X-ray spectrum. To this end, an analytical physical model enabling a rapid calculation of inverse Compton scattering spectra is developed and combined with a genetic algorithm. This strategy's effectiveness is demonstrated by applying the concept at the Munich Compact Light Source, a storage ring-based inverse Compton X-ray source facility. Since the analytical model is computationally very inexpensive, the proposed framework could enable real-time monitoring of inverse Compton X-ray sources or be used as a non-invasive diagnostic based on a single spectrum for the electron beam emittance of storage rings or accelerators.

Collective emotion is often inferred from the tone of mass media, but such emotion is not directly observed. One approximation is to extract sentiment from text and use sentiment indexes as proxies to study the temporal organization of news sentiment. Using a daily index of U.S. economic news sentiment from 24 newspapers (1980-2025), we examine whether the response time of this sentiment process has changed. Although the average balance of positive and negative coverage has remained broadly stable, the persistence of news sentiment states has increased substantially. In dynamical terms, this implies longer residence times in optimistic or pessimistic regimes and weaker short-run correction of sentiment shocks. Complementary statistics show declining sentiment volatility, fewer reversals, and increasing bimodality, i.e. a stronger separation between positive and negative sentiment states. We also find an asymmetry between bursts of negative and positive sentiment, with negative bursts tending to last longer. These patterns are consistent with a minimal endogenous-memory model in which a slowly evolving latent sentiment component becomes more persistent while short-range corrective feedback weakens. The findings indicate a change in the temporal response of the U.S. economic newspaper sentiment index over the last 45 years, with sentiment shocks leaving longer traces than expected under short-memory exponential decay. News-based sentiment is thus better modeled as persistent episodes rather than as daily reactions that reset after each event.

Rising energy demand from data-center and AI applications has renewed interest in reversible computation, where logic need not dissipate heat at every step if information is uncomputed. Implementations have so far been classical: adiabatic CMOS recovers part of the switching energy but still moves thousands of $k_BT$ per logic node at room temperature. Here we propose classical reversible logic implemented by coherent spin dynamics in a spin quantum-dot array, with inputs and outputs in classical basis states and no algorithmic use of superposition. The same spin stores, transports, and computes, with unitary rotation replacing irreversible switching. The universal building block is an iToffoli gate driven by DC voltage pulses and exchange between hole spins in Ge/SiGe quantum dots. Simulations with realistic model parameters reproduce the Toffoli truth table and yield a testable error landscape. Because shuttling transports the bit without measurement, logic and data movement remain unitary until readout. Millivolt pulses on femtofarad gates with superconducting lines dissipate only dielectric loss and have no thermodynamic floor. With the loss parameters assumed for a demonstrated device the gate energy is $\sim 10^{2}\,k_BT\ln 2$ at 4 K; at a design point within reach of existing devices it can fall below the Landauer scale $k_BT\ln 2$, five to seven orders of magnitude less than a CMOS Toffoli. The same semiconductor hardware therefore serves both purposes, supporting quantum algorithms when superposition is used and classical reversible logic otherwise.

We investigate the estimation of bath-induced coherence in a finite quantum system interacting with thermal reservoirs. Enhancement of coherence estimation is transient and the estimation precision totally disappears at the steady state despite the system retaining finite coherence. By analyzing the full Liouvillian eigenspectrum, we demonstrate that the optimal sensing window emerges from the competition between identifiable contributory modes' temporal relaxation and statistical importance. Neither is the linear inverse scaling of Liouvillian gap with transient optimal time a signature of unimodal contribution to optimal sensing, nor is the existence of multimodal dynamics a signature of nonlinear scaling. The inverse Liouvillian gap does not obey any general scaling with the optimal sensing time of coherence and we prove our numerical results analytically using a general Markovian framework. We further show that coupling the finite system to a quantum cavity and maintaining a thermal bias, transforms the transient metrological optimization into a sustained steady-state resource.

Lunar PNT architectures, NASA's Lunar Augmented Navigation Service (LANS), ESA's Moonlight, and allied concepts, place a small number of satellites in elliptical lunar frozen orbits (ELFO) to serve the south-polar region prioritized for exploration. We report a result that reframes the design trade: for a user at the lunar south pole, the satellite count needed to reach good geometry is roughly double what is currently planned, because the visible satellites cluster into a small solid angle overhead and dilution of precision is limited by their angular spread rather than their number. In a time-averaged simulation, orbit-only ELFO constellations of the planned size (4 to 6 satellites) give a south-polar median geometric DOP (GDOP) of 16 to 21, far worse than the GDOP of about 6 routine for terrestrial GNSS, and the constellation must grow to about 12 satellites before the median GDOP crosses 6. We then show that a small number of surface ranging beacons, a configuration absent from the lunar PNT literature, reaches the same geometric quality far more cheaply by supplying the near-horizon diversity the overhead cluster lacks: three beacons on elevated terrain around a -80 deg latitude user cut the median GDOP from 16.2 to 1.6, a factor of about 10, moving the user from 15% to 100% of the time below GDOP 6, geometry a purely orbital solution reaches only near a 24-satellite fleet. Because there is no atmospheric refraction, surface-to-surface line of sight is bounded by the geometric horizon, so beacon siting on crater rims and elevated terrain is itself a design variable. Surface-beacon augmentation is the lowest-cost, highest-leverage improvement available to lunar south-polar PNT, deployable on assets already planned for the region. The geometry engine is Validated against an independent DOP computation; the constellation and beacon scenario are Modelled.

Computational modeling and simulation have emerged as powerful tools for assessing medical device performance and safety, particularly in silico clinical trials (ISCTs) for automated medical systems. In ventilation, where gas exchange, respiratory mechanics, and patient-ventilator interaction must be managed under evolving pathophysiology, clinical translation of automated control strategies remains slow and resource-intensive. These challenges are particularly relevant for AI-based therapy-control systems, whose data-driven decision-making must be evaluated across heterogeneous and safety-critical patient states that may be sparsely represented in clinical datasets. Mechanistic, physiology-based models provide a complementary and interpretable environment for testing such scenarios. This paper applies a standards-aligned framework for credibility assessment of a computational respiratory model, demonstrated using an automated weaning case study. The framework operationalizes ASME V&V 40 and FDA principles within a structured validation workflow. The model integrates respiratory mechanics, gas exchange, respiratory control, and a ventilator representation, with validation under a defined context of use and explicit questions of interest. Model credibility is assessed through calibration, physiological plausibility, population-based evaluation, and reproduction of emergent behavior. All model requirements derived from the intended context of use are addressed, and gaps are transparently reported. The resulting credibility argument supports applicability of the model for medium-low-risk preclinical ISCTs of automated weaning strategies. Residual limitations relate to the extent of in vivo evidence, population representativeness, and external validation. The validation procedure provides a blueprint for validation of this and similar models in mechanical ventilation and related use cases.

We formulate a symmetry-based hierarchy of strain-derived conjugate fields for ferroaxial order, and demonstrate strain-selected ferroaxial domain control using first-principles calculations. Since ferroaxial order is even under both spatial inversion and time reversal, ordinary electric and magnetic fields cannot serve as universal linear conjugate fields. Homogeneous strain, however, can generate symmetry-allowed piezoaxial fields whose leading order is determined by the parent point group and by the chosen ferroaxial-axis component. For basal-plane strain, the leading field is linear in orthorhombic systems, quadratic in tetragonal systems, and cubic in trigonal and hexagonal systems. Cubic parent groups further split into two classes: cubic-I groups, $23$ and $m\bar{3}$, allow linear full-strain fields for selected axes, whereas cubic-II groups, $432$, $\bar{4}3m$, and $m\bar{3}m$, forbid linear fields and require quadratic or cubic strain combinations depending on the selected axis. In trigonal systems, the basal-plane deviatoric strain with signed amplitude $\varepsilon_{\rm u}$ and principal-axis angle $\theta$ gives the single-axis field $h\propto\varepsilon_{\rm u}^3\sin6\theta$. First-principles calculations for the trigonal ferroaxial compound Na$_2$BaMg(PO$_4$)$_2$ verify both the predicted angular dependence and cubic strain scaling of the ferroaxial domain splitting, and fixed-strain atomic relaxations show strain-selected evolution from the para-axial structure. These results establish static homogeneous strain as a symmetry-allowed conjugate field for ferroaxial order and suggest a route to ferroaxial domain control through strain-field cooling.

Wide-field mid-infrared photothermal (MIP) imaging enables chemically specific microscopy with submicron spatial resolution but remains fundamentally limited by the trade-off between field of view, mid-infrared pulse energy, and spectral tunability. As a result, current wide-field implementations are typically restricted to fields of view below 200 {\mu}m and to either the fingerprint or high-wavenumber spectral regions. Here, we overcome these limitations by developing a wide-field fluorescence-detected mid-infrared photothermal (F-MIP) imaging platform driven by a commercial picosecond optical parametric oscillator (OPO). The system provides pulse energies of up to 360 {\mu}J together with a broad tuning range from 625 to 4327 cm-1, enabling millimeter-scale wide-field imaging in the high-wavenumber regions. We demonstrate a field of view of approximately 1 mm in diameter for fluorescently labeled polystyrene beads while preserving spectral fidelity. Furthermore, the platform enables, to our knowledge, the first wide-field MIP imaging below 900 cm-1. To demonstrate its applicability to biomedical imaging, we performed large-area mosaic imaging of fluorescent tuberculosis-infected tissue sections, providing chemically resolved maps over millimeter-sized sample areas. These results establish broadly tunable OPO-driven F-MIP as a scalable platform for high-throughput vibrational imaging of large biological specimens and advanced materials.

The Fredrickson-Andersen model with hyperparameter $K=1$ is a severely constrained kinetic lattice spin system, such that any site is temporarily blocked from changing its packing state (empty or occupied) if there is one or more occupied nearest neighbors. Starting from a completely random initial configuration with a fraction $\rho$ of sites being occupied, some of the sites may be permanently frozen to their initial state under this severe kinetic constraint. The remaining sites can switch states at least occasionally, and they form the unfrozen subsystem associated with the given initial configuration. In the present work we investigate thermodynamic phase transitions in such unfrozen subsystems of the two-dimensional square lattice and the three-dimensional cubic lattice by extensive numerical simulations. We demonstrate that the giant connected component of the unfrozen subsystem collapses at certain critical value $\rho_{c}$ of initial packing density, with $\rho_c = 0.2475$ for the square lattice and $\rho_c = 0.2809$ for the cubic lattice. This phase transition belongs to the same universality class of the conventional site percolation. We also observe that the ground states (densest packing configurations) experience a continuous crystal-to-glass phase transition at the critical value $\rho^* = 0.1423$ of initial packing density for the cubic lattice. For the two-dimensional square lattice we argue that long-range crystalline order is destroyed in the ground states as long as the initial packing density $\rho$ is positive.

We estimate the impact of Polyakov loop (PL) contributions on electroweak phase transitions (PTs). We show that the PL, which is unavoidable in thermal gauge field theory, tends to tame thermal contributions, thereby softening electroweak PTs and affecting bubble dynamics, nucleation, and the related gravitational-wave spectrum. Including this non-perturbative contribution in perturbative approaches results in a thermal effective potential that disfavours first-order PTs over either second-order PTs or smooth cross-overs. This feature is universal for both fermionic and bosonic contributions to the effective potential.