搜索结果：Reports on progress in physics. Physical Society (Great Britain)

We review a theoretical framework for the cuprate superconductors, rooted in a fractionalized Fermi liquid (FL*) description of the intermediate-temperature pseudogap phase at low doping. The FL* theory predicted hole pockets each of fractional areap/8at hole dopingp, in contrast to the areap/4in spin density wave theory. Magnetotransport measurements, including observation of the Yamaji angle, show clear evidence of hole pocket quasiparticles which can tunnel coherently between square lattice layers, and are consistent with the FL* description. The FL* phase of a single-band model is described using a layer construction with a pair of ancilla qubits on each site: the Ancilla layer model (ALM). Its mean field theory yields hole pockets of areap/8, and matches the gapped photoemission spectrum in the anti-nodal region of the Brillouin zone. Fluctuations are described by the SU(2) gauge theory of a background spin liquid with critical Dirac spinons. A Monte Carlo study of the thermal SU(2) gauge theory transforms the hole pockets into Fermi arcs in photoemission. One route to confinement of FL* upon lowering temperature yields ad-wave superconductor via a Kosterlitz-Thouless transition ofh/(2e)vortices, with nodal Bogoliubov quasiparticles featuring anisotropic velocities and vortices surrounded by charge order halos. An alternative route yields a charge-ordered metallic state that has quantum oscillations consistent with observations. These confinement transitions are driven by the condensation of a SU(2) fundamental Higgs field, which also provides a fractionalized description of intertwined orders. Increasing doping from the FL* phase in the ALM drives a transition to a conventional FL at large doping, passing through an intermediate strange metal regime. We formulate a theory of the FL*-FL metal-metal transition without a symmetry-breaking order parameter, using a critical quantum 'charge' liquid of mobile electrons in the presence of disorder, developed via an extension of the Sachdev-Ye-Kitaev model to two spatial dimensions. At low temperatures, and across optimal and over doping, we address the regimes of extended non-FL behavior by Griffiths effects near quantum phase transitions in disordered metals.Partly based on lectures by S S atBoulder School 2025, Dynamics of Strongly Correlated Electrons, 14-18 July.Lecture videos.Joint ICTP-WE Heraeus School and Workshop on Advances in Quantum Matter: Pushing the Boundaries, ICTP, Trieste, 4, 6 August 2025.Lecture videos.School on Quantum Dynamics of Matter, Light and Information, ICTP, Trieste, 18, 19 August 2025.Lecture videos.Croucher Advanced Study Institute for Fractional Chern Insulators, University of Hong Kong, 4, 5 September 2025.Lecture slides.Advanced School and Conference on Quantum Matter, ICTP Trieste, 1-12 December 2025.Lecture Notes.Lecture videos.

Auger photoelectron coincidence spectroscopy (APECS) has emerged as a powerful tool for probing electron-electron correlation in solids. When a photoexcited core hole decays via a core-valence-valence Auger transition, two valence holes are created in the final state. Consequently, the line shape of the Auger electron spectrum is influenced by both Coulomb and exchange interactions between the two holes. By simultaneously detecting the photoelectron and Auger electron emitted from a single photoionization event, APECS measurements place constraints on the two final state holes, enabling one to independently measure Coulomb and exchange correlation energies. This review highlights the key advantages of APECS over other electron spectroscopic techniques including separating overlapping spectral features, removing the background signal from inelastically scattered electrons, enhanced surface sensitivity and site specificity. It also cites examples of how these attributes can be used to investigate the properties of solids in an unprecedented manner. To aid in understanding APECS data and assist in experimental design, a phenomenological model for the probability of electron pair emission as a function of the photo- and Auger electron kinetic energies and emission angles ispresented. The model is applied to a hypotheticalsolid, demonstrating how the contribution to APECS spectrum of final states with different spin configurations depends on these experimental parameters. A summary of results obtained by performing one-dimensional (as a function of Auger [EA]orphotoelectron [EP] kinetic energy), two-dimensional (parallel detection ofEAandEP) and angle-resolved (AR) (as a function ofEAat specific photo- and Auger electron emission angles) APECS measurements is presented. In particular, measurements of ferromagnetic metals and antiferromagnetic transition metal oxides demonstrate how AR-APECS is a powerful tool for independently measuring Coulomb and exchange correlation energies. Finally, potential future applications of APECS and further developments of this experimental technique are discussed.

Quasicrystals are ubiquitous in nature. They represent unique aperiodic materials featuring long-range order that occupy an intermediate niche between exactly periodic and disordered materials. These properties are reflected in the unusual evolutionary dynamics of excitations and unique localization properties of linear eigenmodes supported by quasicrystals. In particular, being the structures characterized by discrete rotational symmetryCνof orderν, photonic quasicrystals can support the stable propagation of linear vortex-carrying light beams and vortex solitons. However, the impact of discrete rotational symmetryνof quasicrystals on the properties of vortex light states has not been investigated so far, as only the systems constructed using the simplest Penrose tiling or corresponding optically induced Penrose lattices are considered in this context. Here, we propose a broad class of quasicrystals with global topological defects-disclinations-introduced into their structure that allows to produce novel quasicrystalline structures with any desired order of discrete rotational symmetry from the basic Penrose structure. Such global topological deformation substantially enriches the linear spectrum of quasicrystals, allowing them to support new types of linear vortex states and bifurcating from them families of stable thresholdless vortex solitons with unusual intensity and phase distributions. We find two different classes of stable vortex solitons comprising in-phase or out-of-phase pairs of closely located bright spots, with total intensity distribution reflecting a particular discrete rotational symmetry of the quasicrystal with disclination. Remarkably, even low-charge vortex solitons can be stable in quasicrystals with disclinations, whereas stability intervals for them broaden with the decrease of the discrete rotational symmetryCνof quasicrystals. Our results extend the theory of localization in quasicrystals to structures with global topological deformation, highlighting emerging prospects for the robust transmission of power or information arising in these systems.

Intrinsically disordered prion-like low complexity domains (PLCDs) drive phase transitions that underlie the biogenesis of many biomolecular condensates. Here, we report results from large-scale Monte Carlo simulations on lattices aided by computations of Binder cumulants and rigorous finite-size scaling. These approaches enable accurate mapping of the critical regime and computations of the full binodal of an archetypal PLCD. This weakly associating polymer undergoes phase separation coupled to percolation. Between the lowest temperature and the critical point, the concentrations along the left arm of the binodal vary by four orders of magnitude. The overlap line intersects the left arm of the binodal well below the critical point. This, taken together with the intersection of the percolation line and the left arm of the binodal, leads to demarcation of the binodal into three regimes. Regime I is farthest from the critical point. Here, the coexisting dilute phase is akin to a gas of dispersed polymers. The dilute arm of the binodal lies above the overlap line in Regimes II and III. Here, the semidilute nature of dilute phases enables clustering of polymers that is enhanced by intermolecular associations. The coexisting dense phases form confined percolated networks in Regimes I and II. In Regime III, which is closest to the critical point, the dense phase becomes unconfined and fragmented, and the system is defined by two interconnected, system-spanning networks. In addition to mapping the critical point accurately, we evaluated methods for identifying the theta temperature. We find that scaling approaches based on assumptions from two-parameter theories for homopolymers yield erroneous estimates of the theta temperature of an archetypal PLCD. Accurate estimation of the theta temperature requires direct calculation of the temperature dependence of the two-body interaction coefficient. We discuss implications for inferring solvent quality from scaling analysis of segmental distances of disordered proteins.

Photon condensation in semiconductor microcavities is a transformative technique for engineering quantum states of light at room temperature by tailoring strong but incoherent light-matter interactions. While continuous-wave and electrical pumping offer exceptional prospects for miniaturized quantum photonic technologies, harnessing these requires conceptual advances in understanding non-equilibrium light-matter dynamics in semiconductors. We resolve this challenge through anab initioquantum kinetic theory capturing how Coulomb interactions of optically excited carriers and phonon scattering mediate photon thermalization and condensation in semiconductors. Our microscopic model shows that at high carrier densities, thermalization is dominated by carrier-carrier Coulomb scattering, in clear contrast to the rovibrational relaxation that governs dye-based photon condensates. The theory predicts a rich nonequilibrium phase diagram with thermal, Bose-condensed, multimode, and lasing phases, quantitatively in agreement with recent experiments. Crucially, we identify how cavity detuning controls transitions between equilibrium and gain-dominated regimes, enabling tailored design of coherent light sources. This work thus provides the foundation for semiconductor-based quantum photonic devices operating beyond conventional laser paradigms.

Optical nanotweezers, which integrate nanophotonic structures such as plasmonic antennas, dielectric resonators, and metasurfaces, have emerged as powerful tools for manipulating nanoparticles, biomolecules, and viruses with high precision. However, traditional designs rely heavily on heuristic approaches and simple geometries, limiting performance. Inverse design offers a paradigm shift by using computational optimization methods to discover non-intuitive, high-performance structures for optical trapping. This Review provides an overview of key inverse design methodologies, including adjoint-based optimization, topology optimization, and machine learning approaches, and highlights their broader impact across nanophotonics. We then focus on their application to optical nanotweezers, where recent advances demonstrate enhanced trapping stiffness, reduced optical heating, and tailored trapping landscapes. Representative examples include algorithmic design of plasmonic nanotweezers, topology-optimized plasmonic nanoapertures, inverse-designed dielectric nanocavities, and force-centric designs based on Maxwell stress tensor engineering. Collectively, these studies illustrate how inverse design enables stable, efficient, and versatile optical trapping at the nanoscale. Despite these advances, challenges remain in fabrication, computational cost, and the interpretability of optimized structures. We conclude with a perspective on future directions, emphasising opportunities in reconfigurable tweezers, lab-on-a-chip integration, and quantum nanophotonics. By bridging photonic optimization with nanoscale manipulation, inverse-designed optical nanotweezers offer promising opportunities for future applications in biophysics, materials science, and quantum technologies.

In solution, electrically like-charged particles can experience a strong and long-ranged attraction that leads to the formation of stable, slowly reorganizing clusters. The attractive force underpinning this spontaneous organization process has been shown to depend on both the sign of charge of the particle and the nature of the solvent medium. The origin of the attraction has been ascribed to the preferential orientation of solvent molecules at the object-electrolyte interface. Here, we use optical imaging to directly measure the spatial profile of the potential of mean force between isolated pairs of charged microspheres. Working with particles carrying a variety of surface chemistries we find that the range of the electrosolvation attraction is substantially longer than previously held. In particular we show that particles carrying strongly anionic surface coatings composed of DNA or phospholipid bilayers display long-range attraction. We further find that the length scale governing the decay of the attractive force can depend on the properties of the interacting particles. This contrasts with the canonical expectation that the screening length governing the interaction of charged particles in solution depends exclusively on the properties of the intervening electrolyte medium. The observations point to significant departures from current thinking, and the likely need for a model of interactions that accounts for the molecular nature of the solvent, its interfacial behaviour, and spatial correlations. Finally, a strong and long-ranged attraction mediated by anionic matter constituting lipid membranes and chromatin could carry far-reaching implications for organization and structure formation in biology.

Contrary to the reciprocal electrical transport constrained by the Onsager relations, nonreciprocal electrical transport arises in noncentrosymmetric systems where the resistance depends on the direction of current flow or external stimuli such as a magnetic field. Governed by symmetry-dependent charge dynamics, these responses appear as nonreciprocal charge transport (NCT) in the longitudinal direction and the nonlinear Hall effect (NLHE) in the transverse direction. Recent theoretical advances have expanded the range of mechanisms and material platforms capable of hosting nonreciprocal signals, revealing the role of hidden band-geometric properties. In parallel, experimental developments have exploited these effects for practical devices, offering promising alternatives to semiconductor-based rectifiers and wireless components, with advantages in broadband operation, ultrafast response, and high energy efficiency. In this review, we summarize electrical measurement techniques and characteristic transport signatures for identifying nonreciprocal phenomena and uncovering their underlying symmetry. We provide a comprehensive discussion of the fundamental mechanisms underlying NCT and NLHE, organized through representative material systems, and a subsequent examination of strategies for artificially inducing and enhancing nonreciprocity. Finally, we evaluate the technological perspectives of nonreciprocal electrical transport for electronic applications, along with key challenges and opportunities for scalable device implementation. By synthesizing current progress, this review aims to guide materials discovery and device innovation, and to inspire exploration of new symmetry settings and unconventional routes toward enhanced nonreciprocal functionalities.

Piezoelectricβ-glycine is a promising molecular crystal, yet its controlled preparation remains challenging. Current nanoconfinement strategies, which rely primarily on rigid templates or simulations, cannot reliably capture the intrinsic confinement regime that leads toβ-phase formation. Here, we propose electric-field-driven nanoconfinement as a one-step, continuous, and interface-free approach to investigate glycine crystallization and to define the confinement regime that yields theβ-phase. We produced glycine nanoparticles via electrohydrodynamic spraying under a direct current field, automatically varying the spraying height to modulate nanoconfinement during nucleation and growth. Structural, morphological, and piezoelectric characterizations reveal that pureβ-glycine forms within a crystal radius range of 5-120 nm. By integrating these findings with thermodynamic and kinetic analysis, we elucidate the mechanism ofβ-phase formation and construct a crystallization phase map that delineates the confinement conditions necessary for its stabilization. This work identifies the critical nanoconfinement parameters for accessing piezoelectricβ-glycine and provides fundamental insights into polymorph control in molecular crystalline materials.

In twisted bilayer graphene (TBG) devices, local strain frequently coexists with the twist-angle-dependent moiré superlattice and strongly influences the electronic properties, yet their combined effects remain incompletely understood. Here, using low-temperature scanning tunneling microscopy, we study a TBG device exhibiting both a continuous twist-angle gradient from 0.35° to 1.30° and spatially varying strain fields, spanning the first (1.1°), second (0.5°), and third (0.3°) magic angles. We directly visualize the evolution of flat and remote bands in both energy and real space with atomic resolution. By comparing regions dominated by shear, uniaxial, and mixed strain, we find that shear strain plays a decisive role in controlling flat-band separation, linewidth, and spectral-weight redistribution. Near the first magic angle, this manifests as an anomalous transfer of spectral weight between the two flat-band peaks, accompanied by an unusual spatial dispersion of flat-band states within a moiré unit cell. In contrast, the energy of the remote bands provides a robust, strain-insensitive indicator of the local twist angle. Structural analysis reveals that shear strain dominates over large regions of the sample, consistent with its lower elastic energy cost. All observations are quantitatively reproduced by a continuum model incorporating heterostrain and electron-electron interactions, establishing shear strain as a central ingredient in shaping the low-energy electronic landscape of TBG.

BACKGROUND: Efforts to establish the 2015 baseline and monitor early implementation of the UN Sustainable Development Goals (SDGs) highlight both great potential for and threats to improving health by 2030. To fully deliver on the SDG aim of "leaving no one behind", it is increasingly important to examine the health-related SDGs beyond national-level estimates. As part of the Global Burden of Diseases, Injuries, and Risk Factors Study 2017 (GBD 2017), we measured progress on 41 of 52 health-related SDG indicators and estimated the health-related SDG index for 195 countries and territories for the period 1990-2017, projected indicators to 2030, and analysed global attainment. METHODS: We measured progress on 41 health-related SDG indicators from 1990 to 2017, an increase of four indicators since GBD 2016 (new indicators were health worker density, sexual violence by non-intimate partners, population census status, and prevalence of physical and sexual violence [reported separately]). We also improved the measurement of several previously reported indicators. We constructed national-level estimates and, for a subset of health-related SDGs, examined indicator-level differences by sex and Socio-demographic Index (SDI) quintile. We also did subnational assessments of performance for selected countries. To construct the health-related SDG index, we transformed the value for each indicator on a scale of 0-100, with 0 as the 2·5th percentile and 100 as the 97·5th percentile of 1000 draws calculated from 1990 to 2030, and took the geometric mean of the scaled indicators by target. To generate projections through 2030, we used a forecasting framework that drew estimates from the broader GBD study and used weighted averages of indicator-specific and country-specific annualised rates of change from 1990 to 2017 to inform future estimates. We assessed attainment of indicators with defined targets in two ways: first, using mean values projected for 2030, and then using the probability of attainment in 2030 calculated from 1000 draws. We also did a global attainment analysis of the feasibility of attaining SDG targets on the basis of past trends. Using 2015 global averages of indicators with defined SDG targets, we calculated the global annualised rates of change required from 2015 to 2030 to meet these targets, and then identified in what percentiles the required global annualised rates of change fell in the distribution of country-level rates of change from 1990 to 2015. We took the mean of these global percentile values across indicators and applied the past rate of change at this mean global percentile to all health-related SDG indicators, irrespective of target definition, to estimate the equivalent 2030 global average value and percentage change from 2015 to 2030 for each indicator. FINDINGS: The global median health-related SDG index in 2017 was 59·4 (IQR 35·4-67·3), ranging from a low of 11·6 (95% uncertainty interval 9·6-14·0) to a high of 84·9 (83·1-86·7). SDG index values in countries assessed at the subnational level varied substantially, particularly in China and India, although scores in Japan and the UK were more homogeneous. Indicators also varied by SDI quintile and sex, with males having worse outcomes than females for non-communicable disease (NCD) mortality, alcohol use, and smoking, among others. Most countries were projected to have a higher health-related SDG index in 2030 than in 2017, while country-level probabilities of attainment by 2030 varied widely by indicator. Under-5 mortality, neonatal mortality, maternal mortality ratio, and malaria indicators had the most countries with at least 95% probability of target attainment. Other indicators, including NCD mortality and suicide mortality, had no countries projected to meet corresponding SDG targets on the basis of projected mean values for 2030 but showed some probability of attainment by 2030. For some indicators, including child malnutrition, several infectious diseases, and most violence measures, the annualised rates of change required to meet SDG targets far exceeded the pace of progress achieved by any country in the recent past. We found that applying the mean global annualised rate of change to indicators without defined targets would equate to about 19% and 22% reductions in global smoking and alcohol consumption, respectively; a 47% decline in adolescent birth rates; and a more than 85% increase in health worker density per 1000 population by 2030. INTERPRETATION: The GBD study offers a unique, robust platform for monitoring the health-related SDGs across demographic and geographic dimensions. Our findings underscore the importance of increased collection and analysis of disaggregated data and highlight where more deliberate design or targeting of interventions could accelerate progress in attaining the SDGs. Current projections show that many health-related SDG indicators, NCDs, NCD-related risks, and violence-related indicators will require a concerted shift away from what might have driven past gains-curative interventions in the case of NCDs-towards multisectoral, prevention-oriented policy action and investments to achieve SDG aims. Notably, several targets, if they are to be met by 2030, demand a pace of progress that no country has achieved in the recent past. The future is fundamentally uncertain, and no model can fully predict what breakthroughs or events might alter the course of the SDGs. What is clear is that our actions-or inaction-today will ultimately dictate how close the world, collectively, can get to leaving no one behind by 2030. FUNDING: Bill & Melinda Gates Foundation.

Exceptional points (EPs) exhibit strongly enhanced spectral responses and are therefore promising candidates for sensing applications. Whether these non-Hermitian degeneracies provide a genuine advantage in the quantum regime has been the subject of ongoing debate. Here, we address this issue within a scattering-matrix formalism for sensing with coherent light, which allows the quantum Fisher information (QFI) to be evaluated directly from experimentally accessible scattering data without introducing additional noise channels beyond those inherent to the scattering process. We analyze both nondegenerate and degenerate scattering-matrix poles, including EPs of arbitrary order, and show that the QFI per incoming photon flux is bounded and controlled by three key factors: the decay rate of the resonant mode, the strength of the spectral response associated with non-normality, and the adjustment between the scattering states and the information source. For spatially localized perturbations, this implies that the maximal QFI achievable by wavefront shaping is fully determined by the local density of states at the perturbation site. Within this framework, we demonstrate that EPs can enhance the QFI compared to isolated modes or diabolic points with identical decay rates, and that the QFI can be further increased by moving away from the EP toward parameter regimes where non-Hermitian linewidth splitting reduces the decay rate of one mode. We further show that sufficiently small additional internal losses do not alter this overall picture, thereby providing a unified and experimentally relevant perspective on the design of quantum-limited non-Hermitian sensors.

This paper proposed an optical detection mechanism that utilized orthogonal phase modulation (OPM) and Lissajous mode decoupling within a light-induced thermoelastic spectroscopy (LITES) sensor for the first time, enabling real-time multi-component gas sensing. By establishing a two-dimensional forced vibration model of a quartz tuning fork (QTF) under dual-path OPM, it revealed the vibration mode coupling mechanism induced by non-ideal phase and amplitude conditions, thereby providing a theoretical basis and optimization pathway for suppressing channel crosstalk. In the OPM-LITES sensor, two continuous-wave distributed feedback lasers were modulated by sinusoidal waves with the same frequency (f0/2, wheref0is the resonant frequency of the QTF) but a phase difference of 45°. The combined beam, after wavelength division multiplexing, co-excited the self-designed low-frequency QTF. The piezoelectric signal generated by the QTF underwent orthogonal demodulation via a lock-in amplifier (LIA). The concentration information for the two gases was independently retrieved from the decoupledX-component andY-component of the LIA. Experimental results demonstrated that the OPM-LITES sensor exhibited excellent linear responses to both methane (CH4) and acetylene (C2H2), with average relative systematic errors of 0.54% and 0.79%, and maximum relative errors of 1.72% and 1.38%, respectively. Allan deviation analysis indicated that the minimum detection limits (MDLs) for CH4and C2H2reached 0.32 ppm and 0.29 ppm, with normalized noise-equivalent absorption coefficients of 5.09 × 10-9cm-1·W·Hz-1/2and 6.18 × 10-9cm-1·W·Hz-1/2, respectively. This study not only provided a simple and efficient solution for real-time multi-component gas detection but also established a novel theoretical framework for mode decoupling and signal processing in spectroscopic sensing.

Band structure analysis is central to understanding wave propagation in periodic media; however, it becomes challenging in open systems owing to energy leakage. Photonic crystal (PhC) slabs exemplify such systems, featuring periodicity in thex-yplane and finite extent in thez-direction, and supporting diverse guided-mode resonances whose interactions give rise to phenomena such as bound states in the continuum (BICs), exceptional points (EPs), and circular polarisation states. Although numerical simulations can reveal these effects, effective non-Hermitian Hamiltonians are often employed to elucidate the underlying physical mechanisms. This approach, however, relies on manually selected resonant modes and may suffer from basis incompleteness. Here, a systematic first-principles approach is presented to derive the complex band structure. The minimal channels in the scattering matrix, either open or closed, are determined by the number of propagating bulk Bloch waves. The interactions between these waves fully reveal the complex band structure. For instance, two Bloch waves predict the leading-order imaginary frequencyω''and identify accidental BICs, each associated with a dual Fabry-Pérot mode, whereas three waves reveal robust Friedrich-Wintgen and symmetry-protected BICs together with the associated linewidth behaviours. Orthogonally polarised waves are further incorporated to characterise far-field polarisation and EPs. When extended to a two-dimensional periodic structure, this framework accurately predictsω'', encompasses all known BICs, and tracks their evolution with system parameters. Overall, this first-principles approach provides a unified foundation for studying complex band structure and facilitates the exploration of light confinement in periodic media.

Strain relaxation at lattice-mismatched interfaces is critical for epitaxial growth and high-quality single-crystal films. While van der Waals (vdW) epitaxy is considered as a promising platform due to its high tolerance to lattice mismatch, its actual response to lattice mismatch remains largely unexplored. Here, we investigate the effect of lattice mismatch on vdW interfaces by epitaxially growing MoS2on WS2or WSe2substrate. annular dark-field scanning transmission electron microscopy reveals that MoS2/WS2with a negligible lattice mismatch of ∼0.22% forms a fully commensurate structure, whereas MoS2/WSe2with a large lattice mismatch of ∼3.96% exhibits non-uniform moiré patterns, characteristic of an incommensurate interface. Detailed analysis shows that the MoS2/WS2hetero-bilayers exhibit perfectly aligned structure through compression of MoS2, whereas the MoS2/WSe2hetero-bilayers show elongation and rotation of moiré orientation driven by tensile strain. Notably, even small twist angles induce significant changes in moiré orientation, resulting in bent fringes that are indicative of local rotational distortions. Large lattice mismatch drives localized lattice distortion, where rotation of the MoS2lattice emerges as an energetically favorable mechanism for strain release, in contrast to commensurate alignment in small-mismatch systems. Our results establish moiré pattern analysis as a powerful framework for directly visualizing spatially varying strain and its relaxation pathways in vdW hetero-bilayers. Our work reveals previously inaccessible interfacial deformation modes in vdW hetero-bilayers and establishes moiré analysis as a powerful platform for strain engineering in 2D electronic and optoelectronic materials.

The relaxation of stochastic systems after sudden perturbations is constrained by speed limits and often reveals memory effects that hinder attempts to accelerate their dynamics. Here we demonstrate Kovacs-type nonmonotonic relaxation in the electro-orientation of non-spherical nanoparticles and show how this memory effect limits simple acceleration protocols. Experimentally, the orientational dynamics is monitored optically through field-induced birefringence, which is proportional to the nematic order parameter. When an AC electric field is first set to an extreme value until the birefringence reaches its target and is then switched to the target field (matched two-step protocol), the relaxation exhibits a characteristic Kovacs shoulder. We interpret this behavior within a theoretical framework based on the Smoluchowski equation for the orientational probability density. In the high-frequency AC regime, orientational relaxation is governed by induced dipoles, and the observed memory effect originates from polydispersity, which generates a spectrum of rotational diffusion coefficients and hence multiscale relaxation. Building on this insight, we design protocols that mitigate the detrimental effect of memory by sequentially suppressing the slowest active relaxation mode. Experiments on nanoparticle suspensions with different properties confirm these mechanisms, and we demonstrate substantial reductions in relaxation time compared with single quenches and matched two-step protocols with NaMt suspensions. More broadly, these results illustrate how memory effects emerge when many degrees of freedom are steered with a single control parameter and provide an experimentally accessible strategy for controlling multiscale stochastic dynamics.

Leveraging membrane-dominated deformation modes, plate lattice metamaterials exhibit superior stiffness, strength, and toughness amongst all lattice metamaterials. Beyond mechanical performances, plate lattices are also emerging as versatile platforms for harnessing a broad spectrum of physical properties, including acoustical, thermal, and vibrational functionalities. This review presents a comprehensive overview of the design principles, classification schemes, underlying mechanisms, and multiphysical properties of plate lattice metamaterials. Architecturally, we propose a classification into three categories: (i) pure plates, (ii) perforated plates, and (iii) hybrid plates. In terms of functions, pure plate lattices maximize mechanical efficiency through in-plane stress transfer; perforated plates enable manufacturability and offer acoustic and thermal active geometries via engineered porosity; hybrid plates integrate truss or other elements to enhance vibration attenuation. The key property-governing mechanisms, such as membrane stress, resonance behaviors, Bragg scattering, forced convection, are deeply explained. We further highlight the intrinsic interplay between different physical responses, illustrating how a single geometric design can concurrently harness multiple functionalities. The review concludes with a forward-looking perspective on emerging applications and the integration of advanced physics-informed methods to accelerate the optimization and implementation of multifunctional plate lattices.

In addition to topological lattice defects such as dislocations and disclinations, crystals are also accompanied by unavoidable ordinary defects, devoid of any non-trivial geometry or topology, among which vacancies, Schottky defects, substitutions, interstitials, and Frenkel pairs are the most common. In this work, we demonstrate that these ubiquitous ordinary lattice defects, although geometrically trivial, can nonetheless serve as universal probes of the non-trivial topology of electronic Bloch bands, and any change in the local topological environment in an otherwise normal insulator in terms of mid-gap bound states in their vicinity. We theoretically establish these generic findings by implementing a minimal model Hamiltonian describing time-reversal symmetry breaking topological and normal insulators on a square lattice, fostering such point defects. The defect-bound mid-gap modes are also shown to be robust against sufficiently weak random point-like charge impurities. Furthermore, we showcase experimental observation of such bound states by embedding ordinary crystal defects in two-dimensional acoustic Chern lattices, where precision-controlled hopping amplitudes are implemented via active meta-atoms and Green's-function-based spectroscopy is used to reconstruct spectra and eigenstates. Our combined theory-experiment study establishes ordinary lattice defects as probes of topology that should be germane in crystals of any symmetry and dimension, raising the possibility of arresting localized Majorana modes near such defects in the bulk of topological superconductors and to emulate ordinary-defect-engineered topological devices.

Computing the subleading logarithmic term in the entanglement entropy (EE) of (2+1)d quantum many-body systems remains a significant challenge, despite its central role in revealing universal information about quantum states and quantum critical points (QCPs). Building on recent algorithmic advances that enable the stable calculation of EE as an exponential observable (Zhouet al2024Phys. Rev. B109165106; Zhanget al2024Phys. Rev. B109205147; Liaoet al2024Phys. Rev. B110235111), we develop abubble basisprojector quantum Monte Carlo (QMC) algorithm to precisely and efficiently compute the universal corner of EE at QCPs in a (2+1)d square-lattice transverse-field Ising model augmented with a four-body interaction. Turning on this interaction allows us to trace an Ising critical line, reaching the tricritical point, and then a line of first-order phase transition. In (2+1)d, the tricritical point is described by the Gaussian theory, where a theoretical calculation of the corner logarithmic term in the 2nd Rényi entropy term is available (Casini and Huerta 2007Nucl. Phys. B764183). Our QMC results are in quantitative agreement with this theoretical value, providing a highly nontrivial benchmark of the algorithm. Furthermore, we also study the Rényi EE at the Ising critical line and on the first-order transition line, obtaining results consistent with theoretical expectations. These findings establish the long-sought connection between the universal values of an exactly solvable limit and those of a strongly correlated regime at (2+1)d.