查看更多>>摘要：Quantum phase transitions are a fascinating area of condensed matter physics.The extension through com-plexification not only broadens the scope of this field but also offers a new framework for understanding criti-cality and its statistical implications.This mini review provides a concise overview of recent developments in complexification,primarily covering finite temperature and equilibrium quantum phase transitions,as well as their connection with dynamical quantum phase transitions and non-Hermitian physics,with a particular focus on the significance of Fisher zeros.Starting from the newly discovered self-similarity phenomenon associated with complex partition functions,we further discuss research on self-similar systems briefly.Finally,we offer a perspective on these aspects.
查看更多>>摘要：Phase transitions and critical phenomena are among the most intriguing phenomena in nature and society.They are classified into first-order phase transitions(FOPTs)and continuous ones.While the latter shows mar-velous phenomena of scaling and universality,whether the former behaves similarly is a long-standing controversial issue.Here we definitely demonstrate complete universal scaling in field driven FOPTs for Langevin equations in both zero and two spatial dimensions by rescaling all parameters and subtracting nonuniversal contributions with singular dimensions from an effective temperature and a special field according to an effective theory.This offers a perspective different from the usual nucleation and growth but conforming to continuous phase transitions to study FOPTs.
查看更多>>摘要：Motivated by the determination for the spin-parity quantum numbers of the X(2370)meson at BESⅢ,we extend our dispersive analysis on hadronic ground states to excited states.The idea is to start with the dispersion relation which a correlation function obeys,and subtract the known ground-state contribution from the involved spectral density.Solving the resultant dispersion relation as an inverse problem with available operator-product-expansion inputs,we extract excited-state masses from the subtracted spectral density.This formalism is verified by means of the application to the series of ρ resonances,which establishes the ρ(770),ρ(1450)and ρ(1700)mesons one by one under the sequential subtraction procedure.Our previous study has suggested the admixture of the f0(1370),f0(1500)and f0(1710)mesons(the η(1760)meson)to be the lightest scalar(pseudoscalar)glueball.The present work predicts that the f0(2200)(X(2370))meson is the first excited scalar(pseudoscalar)glueball.
查看更多>>摘要：We explore the properties of the bottom-quark on-shell mass(Mb)by using its relation to the(M)(S)mass((m)b).At present,this (M)(S)-on-shell relation has been known up to four-loop QCD corrections,which however still has a～2％scale uncertainty by taking the renormalization scale as (m)b(m)b)and varying it within the usual range of[(m)b((m)b)/2,2(m)b((m)b)].The principle of maximum conformality(PMC)is adopted to achieve a more precise MS-on-shell relation by eliminating such scale uncertainty.As a step forward,we also estimate the magnitude of the uncalculated higher-order terms by using the Padé approximation approach.Numerically,by using the MS mass(m)b((m)b)=4.183±0.007GeV as an input,our predicted value for the bottom-quark on-shell mass becomes Mb(≌)5.372+-0.091/0.075 GeV,where the uncertainty is the squared average of the ones caused by △αs(Mz),△(m)b((m)b),and the estimated magnitude of the higher-order terms.
查看更多>>摘要：Strong empirical and phenomenological indications exist for large sea-quark admixtures in the low-lying excited baryons.Investigating the low-lying excited baryon ∑*(1/2-)is important for determining the nature of the low-lying excited baryons.We review the experimental and theoretical progress on the studies of the ∑*(1/2-).Although several candidates have received intensive discussions,such as ∑(1620)and ∑(1480),their existence needs further confirmation.Following the prediction of the unquenched quark models for the ∑*(1/2-),many theoretical works suggested the existence of these states in various processes.Future experimental measurements could shed light on the existence of the low-lying excited ∑*(1/2-)state.
查看更多>>摘要：Thermal quantities,including the the entropy density and gluon spectrum,of quark matter within a box that is finite in the longitudinal direction are calculated using a bag model.Under the assumption of entropy conservation,the corresponding gluon dissociation rate of J/Ψ is studied.It reaches a maximum at a certain longitudinal size Lm,below which the suppression is weak even if the temperature becomes higher than that without the finite size effect,and above which the dissociation rate approaches to the thermodynamic limit gradually with increasing longitudinal size of the fireball.
查看更多>>摘要：Second harmonic generation(SHG)in optical materials serves as important techniques for laser source gen-erations in awkward spectral ranges,physical identities of materials in crystalline symmetry and interfacial configuration.Here,we present a comprehensive review on SHGs in nanowires(NWs),which have been recog-nized as an important element in constructing photonic and optoelectronic devices with compact footprint and high quantum yield.Relying on NW's one-dimensional geometry,its SHG could be employed as a sophisticated spectroscopy to determine the crystal phase and orientation,as well as the internal strain.The enhancements of SHG efficiency in NWs are discussed then,which were realized by hybrid integrating them with two-dimensional materials,nanophotonic and plasmonic structures.Finally,the potential applications of NW SHGs are concluded,including the areas of optical correlators and constructions of on-chip nano-laser sources.
查看更多>>摘要：Site disorder exists in some practical semiconductors and can significantly impact their intrinsic properties both beneficially and detrimentally.However,the uncertain local order and structure pose a challenge for exper-imental and theoretical research.Especially,it hinders the investigation of the effects of the diverse local atomic environments resulting from the site disorder.We employ the special quasi-random structure method to perform first-principles research on connection between local site disorder and electronic/optical properties,using cation-disordered AgBiS2(rock salt phase)as an example.We predict that cation-disordered AgBiS2 has a bandgap ranging from 0.6 to 0.8 eV without spin-orbit coupling and that spin-orbit coupling reduces this by approximately 0.3 eV.We observe the effects of local structural features in the disordered lattice,such as the one-dimensional chain-like aggregation of cations that results in formation of doping energy bands near the band edges,formation and broadening of band-tail states,and the disturbance in the local electrostatic potential,which significantly reduces the bandgap and stability.The influence of these ordered features on the optical properties is confined to alterations in the bandgap and does not markedly affect the joint density of states or optical absorption.Our study provides a research roadmap for exploring the electronic structure of site-disordered semiconductor mate-rials,suggests that the ordered chain-like aggregation of cations is an effective way to regulate the bandgap of AgBiS2,and provides insight into how variations in local order associated with processing can affect properties.
查看更多>>摘要：With the rapid increase in power density of electronic devices,thermal management has become urgent for the electronics industry.Controlling temperature in the back-end-of-line is crucial for maintaining the reliability of integrated circuits,where many atomic-scale interfaces exist.The theoretical models of interface thermal conductance not only accurately predict the values but also help to analyze the underlying mechanism.This review picks up and introduces some representative theoretical models considering interfacial roughness,elastic and inelastic processes,and electron-phonon couplings,etc.Moreover,the limitations and problems of these models are also discussed.
查看更多>>摘要：In the quasi-free electron model,the Fermi surface spreads into a sphere in the Brillouin zone,i.e.,the Fermi sphere.The Fermi sphere exists widely in metal systems,no matter whether the crystal is in a body-center cubic,face-center cubic,or hexagonal close-packed lattice.Here,we report a class of compounds stabilized at high pressure with Rubik's cubic Fermi surface,in which the representative example is Pm3n-CaCl3.Our quantum-mechanical variable-composition evolutionary simulations predict the thermal stabilities of CaCl3,and the tight-binding model reveals that its unique Fermi surface originates from the quasi-one-dimensional interac-tion,structural symmetric protection,and particle-hole symmetry breaking.Furthermore,by its flat and steep band structure,CaCl3 has a huge span of effective mass from 9.08 x 103me(super-heavy)to 5.13 x 10-4me on the Fermi level,which supplies an interesting platform for quasiparticle research.
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