Papers

The behavior of dimensionless quantities defined as ratios of partition functions is analyzed to investigate phase transitions and critical phenomena. At criticality, the universal values of these ratios can be predicted from conformal field theory (CFT) through the modular-invariant partition functions on a torus. We perform numerical calculations using the bond-weighted tensor renormalization group for three two-dimensional models belonging to different universality classes: the Ising model, the three-state Potts model, and the four-state Potts model. The partition-function ratios obey the same finite-size scaling form as the Binder parameter, and their critical values agree well with the universal values predicted by CFT. In the four-state Potts model, we observe logarithmic corrections in the system-size dependence of these ratios.

Achieving efficient n-type doping in AlN, a representative ultrawide bandgap (UWBG) semiconductor, remains a longstanding challenge that limits its application in high-power electronics and deep-ultraviolet optoelectronics. Conventional dopants in AlN often introduce deep levels or form compensating complexes, leading to low free-carrier concentrations. In this work, we combine first-principles defect calculations with a structural search method tailored to explore metastable configurations to systematically investigate donor-type defects in AlN. Our results reveal that the aluminum interstitial ($Al_i$) can exhibit shallow-donor behavior in specific metastable configurations that were previously overlooked. This discovery expands the understanding of n-type dopability in AlN, and highlights the critical role of metastable defects in modulating electronic properties.

The Fe-O system is fundamental to understanding the composition and properties of the Earth's core. Recent studies have suggested the possible existence of stable, iron-rich FenO compounds at around 215 GPa. Here, we performed crystal-structure searches and fully anharmonic free-energy calculations to investigate the Fe-FeO system under inner-core conditions. We identified Fe2O as a stable phase and constructed its high P-T phase diagram. Fe2O undergoes a hexagonal-to-tetragonal transition with increasing pressure and temperature. It remains thermodynamically stable against decomposition into Fe and FeO from 200 to 400 GPa and at high temperatures. Although oxygen has been considered nearly absent in the inner core due to its limited solubility, these results suggest that oxygen can, in fact, be incorporated into the solid inner core in the form of an Fe+Fe2O mixture, and can match PREM densities for 53 mol% Fe2O. Our work has the potential to lead to a significant revision of the current understanding of the core's structure and composition.

Electrostatic interactions fundamentally govern the structure and transport of electrolytes. In concentrated electrolytes, however, electrostatic and steric correlations, together with ion-solvent coupling, give rise to complex behavior, such as underscreening, that remains challenging to explain despite extensive theoretical effort. Using molecular dynamics simulations of primitive electrolytes with and without space-filling solvent particles, we elucidate the structural and dynamical crossovers and their connection that emerge with increasing salt concentration. Explicit-solvent electrolytes exhibit a screening transition from a charge-dominated dilute regime to a density-dominated concentrated regime, accompanied by dynamical crossovers in ion self-diffusion and ion-pair lifetimes. These dynamical crossovers display a marked discontinuity, unlike the smoother variation of the screening crossover, which originates from short-range ion-counterion structures. The pronounced growth of ionic clusters leads to a percolation transition only at higher concentrations, whereas the onset of the structural and dynamical crossovers is associated primarily with local ion pairing or small aggregates. Both structural and dynamical behaviors are found to depend sensitively on ion-solvent coupling: implicit-solvent electrolytes exhibit a screening transition between two charge-dominated regimes, accompanied by qualitatively distinct dynamical behavior. Finally, we demonstrate that the diffusion-corrected ion-pair lifetime provides a consistent descriptor linking ionic structure and dynamics across electrolyte systems.

The use of differential phase contrast (DPC) in scanning transmission electron microscopy (STEM) has shown much promise for directly investigating the functional properties of a material system, leveraging the natural coupling between the electron probe and atomic-scale electric fields to map the electrostatic configuration within a sample. However, the high sensitivity of these measurements makes them particularly vulnerable to variations in both sample properties and the configuration of the instrument, stressing the need for robust methodologies to ensure more accurate analyses. In this work, the influence of key instrumental parameters - probe convergence angle, defocus and two-fold astigmatism - on atomic-resolution segmented-detector DPC-STEM measurements is evaluated through extensive image simulations. Results show that the limit of interpretability for a 21 mrad defocused probe is found at a magnitude of 4 nm, where electrostatic field magnitude can be underestimated by about 16 % in overfocus and just above 10 % in underfocus. Equivalent results for a 30 mrad probe demonstrate underestimated values around 30 % at overfocus and 20 % for underfocus, at a lower interpretability limit of 3 nm. Two-fold astigmatism introduces orientation dependent variations that surpass 40 % for magnitudes below 3 nm, but a reduction in sensitivity to the aberration is observed when oriented along detector-segment edges. Overall, the analysis confirms the sensitivity and usefulness of the scattergram-based method and underscores the importance of optimized instrumental alignment for accurate CoM based STEM imaging.

An electronic modulation can retain a substantial local amplitude while its translational coherence is limited by spatial disorder. Its coupling to superconductivity therefore cannot be characterized by a single modulation intensity. We develop a phenomenological formulation of a finite-wave-vector complex electronic envelope coupled to a charged superconducting field. Translation and gauge symmetries constrain the interaction terms, while amplitude, modulation-gradient and condensate-gradient couplings act on distinct responses. The resulting variational equations give uniform coexistence conditions, local stability criteria and phase-gradient coefficients. We define the helicity modulus by a boundary twist, distinguish phase-only from amplitude-weighted correlations, and give an explicit minimal spectral Hamiltonian illustrating how the electronic texture may enter momentum-resolved measurements. The proposed tests use distinct spatial, spectral and stiffness observables; none assumes that a tunnelling gap directly measures condensate amplitude. An explicit kernel expansion yields the leading displacement of the selected wave vector, while the thermodynamic twist response determines phase rigidity independently of charge intensity. The analytical relations and selected numerical responses distinguish amplitude, spatial organization and condensate rigidity within the specified coupled-field model.

Single-crystal X-ray diffraction (SC-XRD) is the gold standard technique to characterize crystal structures in solid state. Despite significant advances in automation for structure solution, the refinement stage still depends heavily on expert intervention and subjective judgment, limiting accessibility and scalability. Herein, we introduce RefrActor, an end-to-end deep learning framework that enables crystal structure determination directly from HKL data. By coupling a physics-informed reciprocal-space encoder (ReciEncoder) with a symmetry-aware diffusion-based generator (StruDiffuser), RefrActor produces fully refined atomic models without requiring initial structural guesses or manual input. Comprehensive evaluations on the GenRef-10k benchmark demonstrates that RefrActor achieves low R1-factors across diverse systems, including low-symmetry, light-atom, and heavy-atom crystals. Case studies further confirm that RefrActor can correctly resolve hydrogen positions, elemental assignments, and moderate disorder. This work establishes a new data-driven paradigm for autonomous crystallographic analysis, offering a foundation for fully automated, high-throughput crystal structure determination.

Parametric amplification is essential for quantum measurement, enabling the amplification of weak microwave signals with minimal added noise. While Josephson-junction-based amplifiers have become standard in superconducting quantum circuits, their magnetic sensitivity, limited saturation power, and sub-kelvin operating requirements motivate the development of alternative nonlinear platforms. Here we demonstrate a two-mode kinetic-inductance parametric amplifier based on a pair of capacitively coupled Kerr-nonlinear resonators fabricated from NbTiN and NbN thin films. The distributed Kerr nonlinearity of these materials enables nondegenerate four-wave-mixing amplification with gains approaching 40 dB, gain-bandwidth products up to 6.9 MHz, and 1-dB compression powers two to three orders of magnitude higher than those of state-of-the-art Josephson amplifiers. A coupled-mode theoretical model accurately captures the pump-induced modification of the hybridized modes and quantitatively reproduces the observed signal and idler responses. The NbN device exhibits a significantly larger Kerr coefficient and superior gain-bandwidth performance, highlighting the advantages of high-kinetic-inductance materials. Our results establish coupled kinetic-inductance resonators as a robust platform for broadband, high-power, and magnetically resilient quantum-limited amplification, offering a scalable route for advanced readout in superconducting qubits, spin ensembles, quantum dots, and other microwave-quantum technologies.

Stemming from antiferromagnetic coupling, exchange bias allows inverted hysteresis in a magnetic system. Such room temperature magnetic reversal has yet to be observed in an amorphous antiferromagnet. Furthermore, the impact of this exchange bias effect on its magnetoelectric transport behavior remains a mystery. Here we discovered a zero-field magnetization switching effect in an exchange-biased amorphous antiferromagnet with inverted magnetic hysteresis. This zero-field magnetic reversal was further evidenced by its inverted large anomalous Hall effect. Notably, this collective spin flipping at zero field can occur at room temperature or above room temperature, which may be associated with quantum interference effect due to thermal fluctuation enhanced disorder. Our experimental results offer a way to design room-temperature exchange-biased amorphous antiferromagnets with zero-field multi magnetic-states and large anomalous Hall effect, holding potential for low-power and high-density memory applications.

We investigate quench dynamics in the quantum $S=1/2$ XXZ antiferromagnetic chain with staggered and anisotropic interactions in the flat-band limit. We consider global quenches that interchange odd- and even-bond strengths in a fully dimerized chain, yielding a postquench Hamiltonian with couplings only on even links. Due to the vanishing group velocity of excitations, the system fails to relax, providing an ideal setting to study dynamical topological quantum phase transitions. We show that the $z$-component of the interactions, controlled by the anisotropy $\Delta$, acts as a relevant term that generates additional dynamical quantum phase transitions and induces rich structures in the Loschmidt echo. These transitions are symmetry-protected and robust for quenches between distinct dimerization patterns. Using a Bell-basis representation, we derive closed-form results for entanglement entropies, Loschmidt echoes for finite and infinite systems, and identify both $\Delta$-independent and $\Delta$-dependent critical times. Quantum simulations on IBM Quantum processors demonstrate that key observables can be reliably extracted on noisy intermediate-scale devices without error mitigation.

The bias-reversal symmetry – where reversing an external bias inverts the current without changing its magnitude – is a hallmark of nonequilibrium transport. While this property holds in homogeneous systems such as the asymmetric simple exclusion process, how disorder and its interplay with particle interactions affect this symmetry has remained unclear. Here, we identify a general criterion in disordered exclusion processes showing that the bias-reversal symmetry holds if and only if the local left-right bond-bias ratio is spatially uniform. This criterion provides a practical diagnostic that separates heterogeneous environments into symmetry-preserving and symmetry-breaking classes. Mean-field and numerical analyses reveal that bond disorder preserves the symmetry beyond linear response, whereas site disorder breaks it through an interplay between heterogeneity and particle interactions. Our results demonstrate how environmental disorder and interparticle interactions cooperate to generate asymmetric transport, thereby providing insight that is potentially relevant to transport through biological and artificial nanochannels.

Nematic elastomers are a particular class of liquid crystal elastomers (LCEs) that exhibit both liquid-crystalline order and rubber (entropic) elasticity. This combination makes them stimuli-responsive soft materials with a number of unusual thermo-mechanical properties. They have been proposed for various applications, including soft robotics, enhanced adhesion, and impact resistance. This paper presents a new experimental setup and a comprehensive dataset characterizing the soft behavior of nematic elastomers over a range of temperatures and strain rates. We also fit the results to a recently developed model of nematic elastomers.

Integrating semiconducting and magnetic materials could combine transistor-like operation with nonvolatility and enable architectures such as logic-in-memory. Here, we employ correlated electrical transport and scanning nitrogen-vacancy (NV) center magnetic imaging to elucidate a spin transistor concept that amalgamates vertical and lateral hopping transport inside a 2D antiferromagnetic semiconductor, mechanistically distinct from vertical tunneling devices. Our device, based on a monolayer-bilayer junction in CrSBr, displays giant, gate-tunable magnetoresistance driven by the dual action of electrostatic doping on space-charge-limited lateral conduction and interlayer exchange coupling. Moreover, we visualize a field-trainable, layer-sharing effect that selects between coherent or domain-wall reversal at the spin-flip transition, enabling multilevel, memristive conductance states. Our layer-dependent space charge mechanism for convergent electrical and magnetic control opens opportunities to address limitations in contemporary computing.

The Fe-Si-O ternary system, central to modeling the interiors of terrestrial planets, remains poorly constrained at Terapascal (TPa) pressures characteristic of super-Earth mantles. Using a combination of crystal-structure prediction and ab initio calculations, we identify three ternary compounds stable near 1 TPa: P3 FeSiO4, P3 Fe4Si5O18, and P-3 FeSi2O6. The first two phases are thermodynamically stable at low temperatures, whereas P-3 FeSi2O6 becomes favored above approximately 2000 K. All three are metallic, paramagnetic, and adopt pseudo-binary arrangements derived from the FeO2 and SiO2 end-member structures. Their crystal structures emerge through substitutions of Fe for Si in Fe2P-type SiO2 or of Si for Fe in Pnma-type FeO2, the stable elemental oxides at ~1 TPa. This structural continuity suggests that Fe preferentially substitutes for Si in the canonical Mg-silicates expected at TPa pressures. Notably, these new pseudo-binaries accommodate Fe in six- and nine-fold coordination, in contrast to the eight-fold cubic coordination found in FeO at similar pressures. The thermodynamic conditions under which these phases form from FeO2 and SiO2 mixtures are clarified through quasi-harmonic free-energy calculations. These phases imply a fundamentally different pattern of Fe incorporation into Mg-silicates at TPa pressures compared with that inferred for Earth's mantle, i.e., mainly [Fe]Mg. Their stability may trigger silicate dissociation into oxides ((Mg,Fe)2(Si,Fe)O4 -> 2(Mg,Fe)O + (Si,Fe)O2) at pressures below ~3 TPa, as expected in the Mg-Si-O system, with the extent of dissociation governed by iron content.

The interplay between non-Hermitian topology and disorder remains a central puzzle in open quantum systems. While the non-Hermitian skin effect (NHSE) is known to be robust against weak perturbations, its fate under strong disorder, particularly in the presence of spin-orbit coupling (SOC), is not fully understood. Here, we uncover a Z_2 topological bipolar skin effect in a non-Hermitian Rashba chain, where spin-up and spin-down eigenstates localize at opposite boundaries. By strictly computing the Lyapunov exponents and introducing a biorthogonal spin-separation index, we map the global phase diagram and reveal a hierarchical breakdown of topology. We demonstrate that the Z_2 skin effect is protected against moderate disorder but collapses into a trivial skin phase before the ultimate onset of Anderson localization. Our results establish a distinct regime of disorder-robust topological non-reciprocity, distinguishable from both the trivial bulk limit and the Anderson localized phase.

In this work, we combine the density functional tight-binding (DFTB) approach with a light-matter Hamiltonian beyond the long-wavelength approximation to propagate the dynamics of vibrational polaritons formed by coupling molecular vibrations to confined radiation inside a Fabry-Pérot optical cavity. Here, we develop a parallelized propagation scheme with lightweight inter-CPU communication by exploiting the sparse nature of the light-matter interactions in the real space representation. We find that the computationally expensive Born charges required for our propagation can be replaced with the computationally inexpensive Mulliken charges to obtain qualitatively accurate linear spectra especially when the nonlinearity (arising from molecular vibrations) of the light-matter interaction term is not substantial. However, the same approach may not be suitable to be used for studying cavity modification of energy transport or chemical dynamics as this approximation leads to spurious heating of the light-matter hybrid system. We demonstrate the utility of this on-the-fly approach to compute angle resolved polaritonic spectra of water. We implement our approach as an open-source computational package, CavOTF, which is available on GitHub.

Many years have passed since the conception of the quintessential method of shortcut to adiabaticity known as counterdiabatic driving (or transitionless quantum driving). Yet, this method appears to be energetically cost-free and thus continually challenges the task of quantifying the amount of energy it demands to be accomplished. This paper proposes that the energy cost of controlling a closed quantum system using the counterdiabatic method can also be assessed using the instantaneous excess work during the process and related quantities, as the time-averaged excess work. Starting from the Mandelstam-Tamm bound for driven dynamics, we have shown that the speed-up of counterdiabatic driving is linked with the spreading of energy between the eigenstates of the total Hamiltonian, which is necessarily accompanied by transitions between these eigenstates. Nonetheless, although excess work can be used to quantify energetically these transitions, it is well known that the excess work is zero throughout the entire process under counterdiabatic driving. To recover the excess work as an energetic cost quantifier for counterdiabatic driving, we will propose a different interpretation of the parameters of the counterdiabatic Hamiltonian, leading to an excess work different from zero. We have illustrated our findings with the Landau-Zener model.

Thin sheets, from graphene to biological membranes, exhibit wrinkling, folding, and thermal deformations driven by geometric nonlinearities. They are treated using weakly nonlinear theories such as the Föppl-von Kármán equations, whose reliance on small slopes and a single-valued height field excludes large-slope and non-graph configurations even at small strain. We introduce a geometric reformulation in terms of scalar stress and curvature potentials that preserves the FvK structure while removing the graph restriction. We show that intrinsic symmetries of these potentials, as opposed to symmetries of the configuration, can persist when none is apparent in the embedding, enabling analytical solutions of boundary-value problems inaccessible to the conventional height-based formulation. Finite-element comparisons validate the predictions under strong confinement. Together, the extended validity and tractability open analytical routes to fluctuating membranes, ribbons, and architected sheets.

The fluorescence of triplet excitons and color-centers is strongly dependent on magnetic field that mixes the zero field spin eigenstates that determine the radiative recombination rates back into the singlet ground state through spin-orbit coupling. For films of molecules, and polycrystalline color-centers samples an average over molecular orientations has to be performed to model the magneto-fluorescence lineshapes. This limits our analytical understanding of the lineshapes and complicates the analysis of the fluorescence dependence on magnetic field. Here, we present a framework that allows to average over triplet molecular orientations analytically. Our approach provides very accurate numerical routines computing precisely the averages matrix elements that appear in magneto-fluorescence and semi-analytical approximations that can be used to model experimental traces.

High-density granular active matter is a useful model for dense animal collectives and could be useful for designing reconfigurable materials that can flow or solidify on command. Recent work has demonstrated key similarities and differences between the mechanical response of dense active matter and its sheared passive counterpart, yet a constitutive law that predicts precisely how dense active matter flows or fails remains elusive. Here we study the yielding transition in dense active matter in the limit of slow driving and large persistence times, across a wide range of material preparations. Under shear, materials prepared to be very low energy or ultrastable are brittle, and well-described by elastoplastic constitutive laws. We show that under random active forcing, however, ultrastable materials are always ductile. We develop a modified elastoplastic model that captures and explains these observations, where the key parameter is the correlation length of the input active driving field. We also observe large parameter regimes where the plastic flow is surprisingly well-predicted by the input active driving field and not highly dependent on the structural disorder, suggesting new strategies for control.

We present an experimental method to fabricate centimetric thin elastic capsules with highly uniform thickness and negligible bending stiffness using silicone elastomers. In our experiments, the capsules thickness is tunable at fabrication, while internal pressure and hoop (circumferential) stress are adjustable via hydrostatic inflation once the capsules are filled and immersed in water. Capsules mechanics are probed through hydro-elastic waves generated by weak mechanical perturbations at the capsule interface. By analyzing the surface wave dynamics in the Fourier domain, we extract the in-plane stress and demonstrate that the hydro-elastic waves are exclusively governed by hoop stress. This \reponse{provides a controllable macroscopic analogue of liquid drops} characterised by an effective surface tension, allowing the capsules to be modeled as large-scale “elasto-drops” with an inflation and thickness tunable effective surface tension. \reponse{In this limit, bending stiffness is negligible over the experimentally relevant wavelengths, so that the shell dynamics are governed primarily by in-plane tension.} Our work demonstrates that elasto-drops serve as a robust model system for parametric studies of large-scale \reponse{analogues of} liquid drops with experimentally adjustable surface tension.

We present an approach to the molecular-beam epitaxy of high-Q planar GaAs-based microcavities in which the AlGaAs high-index layers of the distributed Bragg reflectors (DBRs) are replaced by short-period GaAs/AlAs superlattices (digital alloys) with similar optical properties. This design enables a significant reduction of interface roughness, precise control of the quarter-wavelength optical thickness and the effective Al content, suppression of the propagation of structural defects, and efficient tuning of intrinsic absorption at the polariton emission wavelength via optimization of the superlattice parameters. Using this approach, we fabricate a microcavity with a low polariton-lasing threshold of approximately 570 W/cm$^2$ and a high experimental quality factor of about 5.4 x $10^4$. This value exceeds by almost a factor of two the theoretical estimate obtained within an equivalent ternary-alloy model. We demonstrate that accurate modeling of the stop-band characteristics and the Q factor requires incorporating the modified electronic density of states in the superlattice, including quantum-confinement and excitonic effects.

An excitonic approach to the ultrafast optical response of confined semiconductors at elevated densities below the Mott transition is presented. The theory is valid from the coherent regime, where coherent excitonic transitions and biexcitons dominate, to the incoherent regime, where excitonic occupations dominate. Numerical simulations of the $1s$ exciton dynamics during intense circularly polarized pump pulses in two different Coulomb-interaction regimes are performed for two-dimensional semiconductors: Moderate Coulomb interaction is compared with dominating Coulomb interaction with respect to the light-matter interaction strength. The different many-body contributions are disentangled and it is found, that excitonic Rabi oscillations in the Coulomb-dominated regime are considerably less strong. By also comparing circular and linear excitation in a MoSe$_2$ monolayer, it is found, that linear excitation creates a regime, where excitonic Rabi oscillations are almost completely suppressed.

Designing metal-organic frameworks (MOFs) synthesis protocols is currently largely driven by trial-and-error, since we lack fundamental understanding of the molecular level mechanisms that underlie their self-assembly processes. Previous works have studied the nucleation of MOFs, but their growth has never been studied by means of computer simulations, which provide molecular level detail. In this work, we combine constant chemical potential simulations with a particle insertion method to model the growth of the ZIF-8 MOF at varying synthesis temperatures and concentrations of the reactants. Non-classical growth mechanisms triggered by oligomer attachments were detected, with a higher predominance in the most concentrated setups. The newly formed layers preserve the pore-like density profile of the seed crystal but contain defective sites characterized by the presence of 3, 5 and 7 membered rings, typical of amorphous phases. Compared to the amorphous intermediate species obtained at the nucleation part of the self-assembly process previously investigated in our group [Chem. Mater., doi: 10.1021/acs.chemmater.5c02028, 2025], larger-sized rings are more common in the grown layer. Moreover, these are favored by increasing reactant concentration and temperature, as is the degree of deviation with respect to the original crystal structure. We computed growth rates for the steady-state regime, and the non-linear tendency with respect to concentration leads us to hypothesize that in these conditions the growth is controlled by the adsorption rather than by the diffusion processes.

Materials utilized by novel energy systems are often studied using weakly correlated mean-field theories. However, if these systems incorporate heavy elements, relativistic effects must be included. Therefore a Kramers unrestricted Coupled Cluster with singles and doubles excitation formalism within a molecular mean-field Exact Two-Component framework (X2C-mmf) using a four-component Dirac-Hartree-Fock (DHF) reference state is presented. The exact X2C-mmf transformed normal-order Hamiltonian incorporates all one-electron and two-electron (2e) contributions from the Coulomb, Gaunt, and Breit operators and is used with the Equation of Motion method to calculate the excitation energies of the alkali group of elements. Using this framework, the effects of 2e Gaunt and Breit integrals are studied. Results demonstrate growing contributions from these integrals to the generated X2C-mmf mean-fields and electronic fine structure calculations with increasing atomic number. Overall, this paper outlines the method and effect of a higher level of accuracy within the X2C-mmf approach and lays the foundation for future theoretical development of relativistic calculations within this framework.

Understanding interfacial heat transfer between polymers and water is crucial for the design of biomaterials, drug delivery platforms, and nanofluidic systems. In this study, we employed all atom molecular dynamics (MD) simulations to quantify the interfacial thermal conductance between a polyethylene glycol (PEG) 36mer chain and explicit water over the temperature range of 280-350 K. To compare the conformational behavior of the PEG chain, we examined its radius of gyration and observed a temperature dependent chain collapse consistent with previous coarse grained models. By employing a transient non equilibrium MD approach, we imposed temperature difference across the interface and analyzed the energy relaxation behavior to compute heat transfer across the polymer water interfaces. Our results demonstrate that both temperature and interfacial interaction strength influence interfacial thermal conductance, with temperature playing the dominant role. Structural factors such as chain conformation and interfacial area were found to mediate the effect of interfacial interaction. Additional analysis of the vibrational density of states (VDOS) and the mean square displacement (MSD) reveal that vibrational coupling has minimal impact on thermal conductance across interfaces, whereas increased water thermal motion enhances energy transfer. These findings highlight the structural and dynamical origins of interfacial thermal conductance and provide atomistic insights into the tuning of interfacial heat transport in molecular systems through temperature and solvent interactions.

Conformal interfaces gluing a pair of two-dimensional conformal field theories enjoy a large degree of universality in terms of the coefficients of reflection and transmission of energy, that describe the scattering of conformal matter at the interface. In this article, we study these coefficients beyond conformality, by gluing a pair of $T\bar T$-deformed 2D CFTs across an interface, which requires the condition $c_L \mu_L = c_R \mu_R $ to be obeyed. We show that, at least when the interface admits a holographic description, the $T\bar T$ deformation of the CFTs can be extended to the interface. We propose a generalization of the linear matching condition in the universal sector of the undeformed ICFT to a non-linear one, which is captured by a universal antisymmetric transmission function of the incoming fluxes. We employ the flow equations of the $T\bar T$-deformed CFTs to compute this function in two special classes of states, namely the non-equilibrium steady state (NESS) and scattering state. We show that the results can also be reproduced using holographic techniques in the bulk dual of these states.

Quantum annealers are emerging as programmable, dynamical experimental platforms for probing strongly correlated spin systems. Yet key thermal assumptions, chiefly a Gibbs-distributed output ensemble, remain unverified in the large-scale regime. Here, we experimentally and quantitatively assess Gibbs sampling fidelity across system sizes spanning over three orders of magnitude. We explore a wide parameter space of coupling strengths, system sizes, annealing times, and D-wave hardware architectures. We find that the naively assumed scaling law for the effective temperature requires a non-negligible, coupling-independent offset that is robust across machines and parameter regimes, quantifying residual non-thermal effects that still conform to an effective Gibbs description. These non-idealities are further reflected in a systematic discrepancy between the physical temperature inferred from the sampled ensemble and the nominal cryogenic temperature of the device. Our results systematically assess the viability of quantum annealers as experimental platforms for probing classical thermodynamics, correct previous assumptions, and provide a physically grounded thermometry framework to benchmark these machines for future thermodynamic experiments.

We introduce a numerical method for computing spectral densities, and apply it to the evaluation of the local density of states (LDOS) of sparse Hamiltonians derived from tight-binding models. The approach, which we call the high-order delta-Chebyshev method, can be viewed as a variant of the popular regularized Chebyshev kernel polynomial method (KPM), but it uses a high-order accurate approximation of the $\delta$-function to achieve rapid convergence to the thermodynamic limit for smooth spectral densities. The costly computational steps are identical to those for KPM, with high-order accuracy achieved by an inexpensive post-processing procedure. We apply the algorithm to tight-binding models of graphene and twisted bilayer graphene, demonstrating high-order convergence to the LDOS at non-singular points.

We prove formally that the momentum-mixing Hatsugai-Kohmoto model (MMHK) is the Hubbard model with a twist. With this result in tow, we rely on the proof of Watanabe's that two models which differ by a twist must have the same bulk physics. Consequently, we have proven that MMHK=Hubbard in the charge sector.