We study the tunnelling dynamics of superfluid Fermi gases trapped in multi-well system along the BEC-BCS crossover. Within the hydrodynamical model and by using the multi-mode approximation, the self-trapping dynamic...We study the tunnelling dynamics of superfluid Fermi gases trapped in multi-well system along the BEC-BCS crossover. Within the hydrodynamical model and by using the multi-mode approximation, the self-trapping dynamics of superfluid Fermi gases in multi-well system are obtained numerically. We find that the self-trapping to diffusion transition strongly depends on the well number. When the well number is less than three, the self-trapped state takes place easier on the BEC side than that on the BCS side. However, when the well number is larger than three, the self-trapped state takes place easier on the BCS side instead of the BEC side. Furthermore, by considering a superfluid of 40K atoms, we obtain the zero-mode and π-mode Josephson frequencies of coherent atomic oscillations in double-well system. It is noteworthy that the Josephson mode, especially, the existence of π-mode frequency strongly depends on the atoms number on the BCS side.展开更多
The temperature and the size dependences of the self-trapping energy of a polaron in a GaAs parabolic quantum dot are investigated by the second order Rayleigh-Schrodinger perturbation method using the framework of th...The temperature and the size dependences of the self-trapping energy of a polaron in a GaAs parabolic quantum dot are investigated by the second order Rayleigh-Schrodinger perturbation method using the framework of the effective mass approximation. The numerical results show that the self-trapping energies of polaron in GaAs parabolic quantum dots shrink with the enhancement of temperature and the size of the quantum dot. The results also indicate that the temperature effect becomes obvious in small quantum dots展开更多
We investigate the self-trapping of a Bose Josephson junction, which is dispersively coupled to a driven optical cavity. The cavity-induced nonlinearity is presented analytically, and its effect results in the appeara...We investigate the self-trapping of a Bose Josephson junction, which is dispersively coupled to a driven optical cavity. The cavity-induced nonlinearity is presented analytically, and its effect results in the appearance of the self-trapping for the Bose-Einstein condensates in the Josephson oscillation regime. In addition, there exists competition between the nonlinearities induced by the interatomic interaction and by the driven cavity for the emergences of self-trapping. Our results show that the driven cavity can be utilized as a possible tool to produce the self-trapping for the condensates with weak interatomic interaction.展开更多
We investigate the properties of the excess charge(electron, hole) introduced into a two-strand biomolecule. We consider the possibility that the stable soliton excitation can be formed due to interaction of excess ch...We investigate the properties of the excess charge(electron, hole) introduced into a two-strand biomolecule. We consider the possibility that the stable soliton excitation can be formed due to interaction of excess charge with the phonon subsystem. The influence of overlap of the molecular orbitals between adjacent structure elements of the macromolecular chain on the soliton properties is discussed. Special attention is paid to the influence of the overlapping of the molecular orbitals between structure elements placed on the different chains. Using the literature values of the basic energy parameters of the two-chain biomolecular structures, possible types of soliton solutions are discussed.展开更多
We investigate the interactions of lattice pbonons with Wannier-Mott exciton, the exciton that has a large radius in two-dimensional molecular lattice, by the method of continuum limit approximation, and obtain that t...We investigate the interactions of lattice pbonons with Wannier-Mott exciton, the exciton that has a large radius in two-dimensional molecular lattice, by the method of continuum limit approximation, and obtain that the self-trapping can also appear in two-dimensional molecular lattice with a harmonic and nonlinear potential. The exciton effect on molecular lattice does not distort the molecular lattice but only makes it localized and the localization can also react, again through phonon coupling, to trap the energy and prevents its dispersion.展开更多
We investigate the interactions of lattice phonons with Frenkel exciton, which has a small radius in a twodimensional discrete molecular lattice, by the virtue of the quasi-discreteness approximation and the method of...We investigate the interactions of lattice phonons with Frenkel exciton, which has a small radius in a twodimensional discrete molecular lattice, by the virtue of the quasi-discreteness approximation and the method of multiplescale, and obtain that the self-trapping can also appear in the two-dimensional discrete molecular lattice with harmonic and nonlinear potential. The excitons＇ effect on the molecular lattice does not distort it but only causes it to localize which enables it to react again through phonon coupling to trap the energy and prevent its dispersion.展开更多
We investigate tunneling and self-trapping of superfluid Fermi gases under a two-mode ansatz in different regimes of the crossover from Bardeen-Cooper-Schrieffer （BCS） superfluid to Bose-Einstein condensates （BEC）...We investigate tunneling and self-trapping of superfluid Fermi gases under a two-mode ansatz in different regimes of the crossover from Bardeen-Cooper-Schrieffer （BCS） superfluid to Bose-Einstein condensates （BEC）. Starting from a generalized equation of state, we derive the coupled equations of relative atom-pair number and relative phase about superfluid Fermi gases in a double-well system and then classify the different oscillation behaviors by the tunneling strength and interactions between atoms. Tunneling and self-trapping behaviors are considered in the whole BCS-BEC crossover in the ease of a symmetric double-well potential. We show that the nonlinear interaction between atoms makes the self-trapping more easily realized in BCS regime than in the BEC regime and stability analysis is also given.展开更多
We investigate the tunneling dynamics of the Fermi gases in an optical lattice in the Bose--Einstein condensation （BEC） regime. The three critical scattering lengths and the system energies are found in different ca...We investigate the tunneling dynamics of the Fermi gases in an optical lattice in the Bose--Einstein condensation （BEC） regime. The three critical scattering lengths and the system energies are found in different cases of Josephson oscillation （JO）, oscillating-phase-type self-trapping （OPTST）, running-phase-type self-trapping （RPTST）, and self-trapping （ST）. It is found that the s-wave scattering lengths have a crucial role on the tunneling dynamics. By adjusting the scattering length in the adiabatic condition, the transition probability changes with the adiabatic periodicity and a rectangular periodic pattern emerges. The periodicity of the rectangular wave depends on the system parameters such as the periodicity of the adjustable parameter, the s-wave scattering length.展开更多
The tungsten are deemed to be the most promising candidates as plasma facing material due to its high melting temperature, good thermal properties, low sputtering yields[1]. In the near surface of plasma facing materi...The tungsten are deemed to be the most promising candidates as plasma facing material due to its high melting temperature, good thermal properties, low sputtering yields[1]. In the near surface of plasma facing materials high densities of interstitials and vacancies are produced in addition to high concentrations of hydrogen and helium (He). He easily are trapped by vacancies, dislocations, grain boundaries to form He bubble nucleation. When no traps are available, He spontaneously form clusters, which result in strong lattice strain. It can be relieved by ejecting one or more matrix atoms to form one or more Frenkel Pairs, i:e:vacancies and self-interstitial atoms. He cluster will be trapped by the vacancy it created, this is a self-trapping event[2].展开更多
through single-site excitation. By changing the initial to the lattices, periodic oscillations of the localized quadruple state becomes a rotating doubly charged undergo charge-flipping when the rotating direction is ...through single-site excitation. By changing the initial to the lattices, periodic oscillations of the localized quadruple state becomes a rotating doubly charged undergo charge-flipping when the rotating direction is orientation of the incident quadruple beam related quadruple mode may be obtained. The localized optical vortex （DCV） during rotation and should reversed.展开更多
Mn^(2+)doping has been adopted as an efficient approach to regulating the luminescence properties of halide perovskite nano-crystals(NCs).However,it is still difficult to understand the interplay of Mn^(2+)luminescenc...Mn^(2+)doping has been adopted as an efficient approach to regulating the luminescence properties of halide perovskite nano-crystals(NCs).However,it is still difficult to understand the interplay of Mn^(2+)luminescence and the matrix self-trapped exciton(STE)emission therein.In this study,Mn^(2+)-doped CsCdCl_(3) NCs are prepared by hot injection,in which CsCdCl_(3) is selected because of its unique crystal structure suitable for STE emission.The blue emission at 441 nm of undoped CsCdCl_(3) NCs originates from the defect states in the NCs.Mn^(2+)doping promotes lattice distortion of CsCdCl_(3) and generates bright orange-red light emission at 656 nm.The en-ergy transfer from the STEs of CsCdCl_(3) to the excited levels of the Mn^(2+)ion is confirmed to be a significant factor in achieving efficient luminescence in CsCdCl_(3):Mn^(2+)NCs.This work highlights the crucial role of energy transfer from STEs to Mn^(2+)dopants in Mn^(2+)-doped halide NCs and lays the groundwork for modifying the luminescence of other metal halide perovskite NCs.展开更多
Ternary metal halides based on Cu(I)and Ag(I)have attracted intensive attention in optoelectronic applications due to their excellent luminescent properties,low toxicity,and robust stability.While the self-trapped exc...Ternary metal halides based on Cu(I)and Ag(I)have attracted intensive attention in optoelectronic applications due to their excellent luminescent properties,low toxicity,and robust stability.While the self-trapped excitons(STEs)emission mechanisms of Cu(I)halides are well understood,the STEs in Ag(I)halides remain less thoroughly explored.This study explores the STE emission efficiency within the A_(2)AgX_(3)(A=Rb,Cs;X=Cl,Br,I)system by identifying three distinct STE states in each material and calculating their configuration coordinate diagrams.We find that the STE emission efficiency in this system is mainly determined by STE stability and influenced by self-trapping and quenching barriers.Moreover,we investigate the impact of structural compactness on emission efficiency and find that the excessive electron–phonon coupling in this system can be reduced by increasing the structural compactness.The atomic packing factor is identified as a low-cost and effective descriptor for predicting STE emission efficiency in both Cs_(2)AgX_(3) and Rb_(2)AgX_(3) systems.These findings can deepen our understanding of STE behavior in metal halide materials and offer valuable insights for the design of efficient STE luminescent materials.The datasets presented in this paper are openly available in Science Data Bank at https://doi.org/10.57760/sciencedb.12094.展开更多
Self-trapping excitons(STEs) emission in metal halides has been a matter of interest, correlating with the strength of electron-phonon coupling in the lattice, which are usually caused by ions with ns~2 electronic str...Self-trapping excitons(STEs) emission in metal halides has been a matter of interest, correlating with the strength of electron-phonon coupling in the lattice, which are usually caused by ions with ns~2 electronic structure. In this work, Sb^(3+)/Te^(4+)ions doped Zn-based halide single crystals(SCs) with two STEs emissions have been synthesized and the possibility of its anti-counterfeiting application was explored.Further, the relationship between the strength of electron-phonon coupling and photoluminescence quantum yields(PLQYs) for STEs in a series of metal halides has been studied. And the semi-empirical range of the Huang-Rhys factors(S) for metal halides with excellent photoluminescence(PL) property has been summarized. This work provides ideas for further research into the relationship between luminescence performance and electron-phonon coupling of metal halides, and also provides a reference for designing the metal halides with high PLQYs.展开更多
Two-dimensional(2D)chiral halide perovskites(CHPs)have attracted broad interest due to their distinct spin-dependent properties and promising applications in chiroptics and spintronics.Here,we report a new type of 2D ...Two-dimensional(2D)chiral halide perovskites(CHPs)have attracted broad interest due to their distinct spin-dependent properties and promising applications in chiroptics and spintronics.Here,we report a new type of 2D CHP single crystals,namely R/S-3BrMBA_(2)PbBr_(4).The chirality of the as-prepared samples is confirmed by exploiting circular dichroism spectroscopy,indicating a successful chirality transfer from chiral organic cations to their inorganic perovskite sublattices.Furthermore,we observed bright photoluminescence spanning from 380 to 750 nm in R/S-3BrMBA_(2)PbBr_(4)crystals at room temperature.Such broad photoluminescence originates from free excitons and self-trapped excitons.In addition,efficient second-harmonic generation(SHG)performance was observed in chiral perovskite single crystals with high circular polarization ratios and non-linear optical circular dichroism.This demonstrates that R/S-3BrMBA_(2)PbBr_(4)crystals can be used to detect and generate left-and righthanded circularly polarized light.Our study provides a new platform to develop high-performance chiroptical and spintronic devices.展开更多
Light-emitting diodes based on lead halide perovskite have attracted great attention due to their outstanding performance.However,their application is plagued by the toxicity of Pb and the poor stability.Herein novel ...Light-emitting diodes based on lead halide perovskite have attracted great attention due to their outstanding performance.However,their application is plagued by the toxicity of Pb and the poor stability.Herein novel copper-based all inorganic perovskite CsCu2I3 with much enhanced stability has been reported with a potential photoluminescence quantum yield(PLQY)over 20%and self-trapped excitons(STE).By taking advantage of its extraordinary thermal stability,we successfully fabricate high-quality CsCu2I3 film through direct vacuum-based deposition(VBD)of CsCu2I3 powder.The resulting film shows almost the same PLQY with the synthesized powder,as well as excellent uniformity and stability.The perovskite light-emitting diodes(Pe-LED)based on the evaporated CsCu2I3 emitting layer achieve a luminescence of 10 cd/m2 and an external quantum efficiency(EQE)of 0.02%.To the best of our knowledge,this is the first CsCu2I3 Pe-LED fabricated by VBD with STE property,which offers a new avenue for lead-free Pe-LED.展开更多
Rare earth ions(RE^(3+))-doped double perovskites have attracted tremendous attention for its fascinating optical properties.Nevertheless,RE^(3+)generally exhibits poor photoluminescence quantum yield(PLQY)for their p...Rare earth ions(RE^(3+))-doped double perovskites have attracted tremendous attention for its fascinating optical properties.Nevertheless,RE^(3+)generally exhibits poor photoluminescence quantum yield(PLQY)for their parity-forbidden 4f-4f transition and the low doping concentration.Herein,we reported Sb^(3+)/Sm^(3+)-codoped rare earth-based double perovskite Cs_(2)Na Lu Cl_(6)that enables efficient visible and nearinfrared(NIR)emission,which stems from self-trapped exciton(STE)and Sm^(3+),respectively.Benefit from up to 72.89%energy transfer efficiency from STE to Sm^(3+)and high doping concentrations due to similar ionic activity between Sm^(3+)and Lu^(3+),thus eruptive PLQY of 74.58%in the visible light region and 23.12%in the NIR light region can be obtained.Moreover,Sb^(3+)/Sm^(3+)-codoped Cs_(2)Na Lu Cl_(6)exhibits tunable emission characteristic in the visible light region under different excitation wavelengths,which can change from blue emission(254 nm excitation)to white emission(365 nm excitation).More particularly,only the NIR emission can be captured by the NIR camera when a 700 nm cutoff filter is added.The excellent stability and unique optical properties of Sb^(3+)/Sm^(3+)-codoped Cs_(2)Na Lu Cl_(6)enable us to demonstrate its applications in NIR light-emitting diode,triple-mode fluorescence anti-counterfeiting and information encryption.These findings provide new inspiration for the application of rare earth-based double perovskite in optoelectronic devices.展开更多
Recently,organic-inorganic hybrid metal halides(HMHs)have attracted extensive attention as promis-ing multifunctional materials by virtue of their structural diversity and tunable photophysical properties.However,it r...Recently,organic-inorganic hybrid metal halides(HMHs)have attracted extensive attention as promis-ing multifunctional materials by virtue of their structural diversity and tunable photophysical properties.However,it remains a challenge to design HMHs with specific functions on demand.Herein,by introduc-ing R/S-methylbenzylamine(R/S-MBA)and doping Sb^(3+),we have achieved both second harmonic gen-eration(SHG)and circularly polarized luminescence(CPL)properties in lead-free indium halides.The introduction of chiral organic cations can break the symmetry and induce the indium halides to crys-tallize in the chiral space group.The Sb^(3+)with ns2 electronic configuration can serve as the dopants to promote the formation of self-trapped excitons,so as to activate highly efficient luminescence.As a re-sult,the as-prepared Sb3+doped(R/S-MBA)3 InCl6 show not only SHG responses but also CPL signals with luminescence dissymmetry factor of−5.3×10^(−3) and 4.7×10^(−3).This work provides a new inspiration for the exploitation of chiral multifunctional materials.展开更多
We report a mechanistic study of excitonic photoluminescence in predesigned hybrid organic-inorganic perovskite(HOIP)systems,i.e.,(DMAEA)Pb_(2)I_(6),(DMAPA)PbI_(4),(DEAEA)Pb_(2)I_(6),and(DEAPA)_(4)Pb_(5)I_(18),featuri...We report a mechanistic study of excitonic photoluminescence in predesigned hybrid organic-inorganic perovskite(HOIP)systems,i.e.,(DMAEA)Pb_(2)I_(6),(DMAPA)PbI_(4),(DEAEA)Pb_(2)I_(6),and(DEAPA)_(4)Pb_(5)I_(18),featuring targeted regulation of organic cations.Starting from the prototype DMAEA(i.e.,2-N,N-dimethylamino-l-ethylamine)for(DMAEA)Pb_(2)I_(6),the other three HOIPs differ only in the extensions with CH_(2)group(s)at the“head”or/and“tail”of DMAEA that is an“alkylated ammonia”.Their crystal structures are constructed and structural distortions are evaluated.The steady-state/transient absorption and emission spectroscopic characterizations,combined with the band-structure calculations,are conducted.The two different photoluminescence(PL)mechanisms are identified,i.e.,PL emissions dominated by free excitons for(DMAPA)PbI_(4)and by self-trapped excitons for(DMAEA)Pb_(2)I_(6),(DEAEA)Pb_(2)I_(6),and(DEAPA)_(4)Pb_(5)I_(18).The self-trapped excitonic effect involved in the latter three HOIPs is quantitatively analyzed.This work would be of guiding value for the design of HOIP systems based on organic-cation engineering,beneficial for the pertinent performance optimization in light-emitting applications.展开更多
Zero-dimensional perovskite materials,characterized by broadband emission caused by self-trapped excitons,are promising materials for stimuli-responsive and photo-writeable encryption.However,existing research is focu...Zero-dimensional perovskite materials,characterized by broadband emission caused by self-trapped excitons,are promising materials for stimuli-responsive and photo-writeable encryption.However,existing research is focused on the effects of structural phase transitions on photophysical properties,and lacks in-depth understanding of the mechanisms of self-trapped excitons emission.Here,we demonstrate that the dehydration reaction in zero-dimensional antimony halide clusters significantly enhances the self-trapped excitons emission without inducing structural phase transition,resulting in a substantial increase in photoluminescence(PL)quantum yield from 3.5%to 91.4%.In-situ X-ray diffraction and PL techniques were employed to shed light on the relationship between the crystal structure and radiative recombination,demonstrating the introduction of rich lattice distortion during the dehydration process.Temperature-dependent PL spectra and transient absorption spectra suggest that the lattice distortion causes the moderate electron-phonon coupling strength and high exciton binding energy,facilitating self-trapped excitons to relax from the non-radiative recombination singlet state to the radiative recombination triplet state,corresponding to the enhanced emission intensity.As a proof of concept,several switchable PL applications have been established in scenarios such as anti-counterfeiting,rewritable luminescent paper,and humidity sensing.This finding elucidates the emission mechanism of self-trapped excitons and provides a novel avenue for designing switchable luminescent materials.展开更多
The impurity-induced localization of two-component Bose-Einstein condensates loaded into deep one-dimensional optical lattices is studied both analytically and numerically. It is shown that, the analytical criteria fo...The impurity-induced localization of two-component Bose-Einstein condensates loaded into deep one-dimensional optical lattices is studied both analytically and numerically. It is shown that, the analytical criteria for self-trapping and moving soliton/breather of the primary-component condensate are modified significantly by an admixture of an impurity component （the second component）. The realization of the self-trapped state and the moving soliton/breather states of the primary-component becomes more easy with the minor admixture of the impurity-component, even if the two components are partly overlapped.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos. 10975114 and 10774120the Natural Science Foundation of Gansu Province of China under Grant No. 1010RJZA012+1 种基金the Natural Science Foundation of Northwest Normal University of China under Grant No. NWNU-KJCXGC-03-48the Youthy Teacher Scientific Research Foundation of Northwest Normal University of China under Grant No. NWNU-LKQN-09-10
文摘We study the tunnelling dynamics of superfluid Fermi gases trapped in multi-well system along the BEC-BCS crossover. Within the hydrodynamical model and by using the multi-mode approximation, the self-trapping dynamics of superfluid Fermi gases in multi-well system are obtained numerically. We find that the self-trapping to diffusion transition strongly depends on the well number. When the well number is less than three, the self-trapped state takes place easier on the BEC side than that on the BCS side. However, when the well number is larger than three, the self-trapped state takes place easier on the BCS side instead of the BEC side. Furthermore, by considering a superfluid of 40K atoms, we obtain the zero-mode and π-mode Josephson frequencies of coherent atomic oscillations in double-well system. It is noteworthy that the Josephson mode, especially, the existence of π-mode frequency strongly depends on the atoms number on the BCS side.
文摘The temperature and the size dependences of the self-trapping energy of a polaron in a GaAs parabolic quantum dot are investigated by the second order Rayleigh-Schrodinger perturbation method using the framework of the effective mass approximation. The numerical results show that the self-trapping energies of polaron in GaAs parabolic quantum dots shrink with the enhancement of temperature and the size of the quantum dot. The results also indicate that the temperature effect becomes obvious in small quantum dots
基金Supported by the National Natural Science Foundation of China under Grant Nos.10847006 and 10874142
文摘We investigate the self-trapping of a Bose Josephson junction, which is dispersively coupled to a driven optical cavity. The cavity-induced nonlinearity is presented analytically, and its effect results in the appearance of the self-trapping for the Bose-Einstein condensates in the Josephson oscillation regime. In addition, there exists competition between the nonlinearities induced by the interatomic interaction and by the driven cavity for the emergences of self-trapping. Our results show that the driven cavity can be utilized as a possible tool to produce the self-trapping for the condensates with weak interatomic interaction.
基金Project supported by the Ministry of Education,Science and Technological Development of the Republic of Serbiathe Ministry of Science and Higher Education of the Russian Federation in the framework of Increase Competitiveness Program of NUST “MISiS” (Grant No.K2-2019-010)the Project within the Cooperation Agreement between the JINR,Dubna,Russian Federation and Ministry of Education and Science of the Republic of Serbia。
文摘We investigate the properties of the excess charge(electron, hole) introduced into a two-strand biomolecule. We consider the possibility that the stable soliton excitation can be formed due to interaction of excess charge with the phonon subsystem. The influence of overlap of the molecular orbitals between adjacent structure elements of the macromolecular chain on the soliton properties is discussed. Special attention is paid to the influence of the overlapping of the molecular orbitals between structure elements placed on the different chains. Using the literature values of the basic energy parameters of the two-chain biomolecular structures, possible types of soliton solutions are discussed.
基金supported by the National Natural Science Foundation of China (Grant No.1057400)the Natural Science Foundation of Heilongjiang Province,China (Grant No.A200506)
文摘We investigate the interactions of lattice pbonons with Wannier-Mott exciton, the exciton that has a large radius in two-dimensional molecular lattice, by the method of continuum limit approximation, and obtain that the self-trapping can also appear in two-dimensional molecular lattice with a harmonic and nonlinear potential. The exciton effect on molecular lattice does not distort the molecular lattice but only makes it localized and the localization can also react, again through phonon coupling, to trap the energy and prevents its dispersion.
基金supported by the National Natural Science Foundation of China (Grant No 1057400)the Natural Science Foundation of Heilongjiang Province of China (Grant No A200506)
文摘We investigate the interactions of lattice phonons with Frenkel exciton, which has a small radius in a twodimensional discrete molecular lattice, by the virtue of the quasi-discreteness approximation and the method of multiplescale, and obtain that the self-trapping can also appear in the two-dimensional discrete molecular lattice with harmonic and nonlinear potential. The excitons＇ effect on the molecular lattice does not distort it but only causes it to localize which enables it to react again through phonon coupling to trap the energy and prevent its dispersion.
基金Supported by Supported by National Natural Science Foundation of China under Grant Nos. 10864006,11047101,11091240227,and11105039by Ph.D. Program Scholarship Fund of East China Normal University under Grant No. 20080044by Research Fund of Jiangsu University of Science and Technology under Grant No. 35051002
文摘We investigate tunneling and self-trapping of superfluid Fermi gases under a two-mode ansatz in different regimes of the crossover from Bardeen-Cooper-Schrieffer （BCS） superfluid to Bose-Einstein condensates （BEC）. Starting from a generalized equation of state, we derive the coupled equations of relative atom-pair number and relative phase about superfluid Fermi gases in a double-well system and then classify the different oscillation behaviors by the tunneling strength and interactions between atoms. Tunneling and self-trapping behaviors are considered in the whole BCS-BEC crossover in the ease of a symmetric double-well potential. We show that the nonlinear interaction between atoms makes the self-trapping more easily realized in BCS regime than in the BEC regime and stability analysis is also given.
基金Project supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA01020304)the National Natural Science Foundation of China(Grant Nos.11275156,91026005,11365020,and 11047010)
文摘We investigate the tunneling dynamics of the Fermi gases in an optical lattice in the Bose--Einstein condensation （BEC） regime. The three critical scattering lengths and the system energies are found in different cases of Josephson oscillation （JO）, oscillating-phase-type self-trapping （OPTST）, running-phase-type self-trapping （RPTST）, and self-trapping （ST）. It is found that the s-wave scattering lengths have a crucial role on the tunneling dynamics. By adjusting the scattering length in the adiabatic condition, the transition probability changes with the adiabatic periodicity and a rectangular periodic pattern emerges. The periodicity of the rectangular wave depends on the system parameters such as the periodicity of the adjustable parameter, the s-wave scattering length.
文摘The tungsten are deemed to be the most promising candidates as plasma facing material due to its high melting temperature, good thermal properties, low sputtering yields[1]. In the near surface of plasma facing materials high densities of interstitials and vacancies are produced in addition to high concentrations of hydrogen and helium (He). He easily are trapped by vacancies, dislocations, grain boundaries to form He bubble nucleation. When no traps are available, He spontaneously form clusters, which result in strong lattice strain. It can be relieved by ejecting one or more matrix atoms to form one or more Frenkel Pairs, i:e:vacancies and self-interstitial atoms. He cluster will be trapped by the vacancy it created, this is a self-trapping event[2].
基金supported by the National"973"Program of China(Nos.2013CB632703 and 2013CB328702)the National Natural Science Foundation of China(Nos.60908002 and 10904078)+4 种基金the International S&T Cooperation Program of China(No.2011DFA52870)the Specialized Research Fund for the Doctoral Program of Higher Education(No.20120031120031)the International Cooperation Program of Tianjin(No.11ZGHHZ01000)the"111"Project(No.B07013)the Program for New Century Excellent Talents in University(No.NCET-10-0507)
文摘through single-site excitation. By changing the initial to the lattices, periodic oscillations of the localized quadruple state becomes a rotating doubly charged undergo charge-flipping when the rotating direction is orientation of the incident quadruple beam related quadruple mode may be obtained. The localized optical vortex （DCV） during rotation and should reversed.
基金supported by the Guangdong Provincial Science&Technology Project(No.2023A0505050084)the National Natural Science Foundation of China(No.22361132525)+1 种基金the Fundamental Research Funds for the Central Universities(No.2023ZYGXZR002)the Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(No.2017BT01X137).
文摘Mn^(2+)doping has been adopted as an efficient approach to regulating the luminescence properties of halide perovskite nano-crystals(NCs).However,it is still difficult to understand the interplay of Mn^(2+)luminescence and the matrix self-trapped exciton(STE)emission therein.In this study,Mn^(2+)-doped CsCdCl_(3) NCs are prepared by hot injection,in which CsCdCl_(3) is selected because of its unique crystal structure suitable for STE emission.The blue emission at 441 nm of undoped CsCdCl_(3) NCs originates from the defect states in the NCs.Mn^(2+)doping promotes lattice distortion of CsCdCl_(3) and generates bright orange-red light emission at 656 nm.The en-ergy transfer from the STEs of CsCdCl_(3) to the excited levels of the Mn^(2+)ion is confirmed to be a significant factor in achieving efficient luminescence in CsCdCl_(3):Mn^(2+)NCs.This work highlights the crucial role of energy transfer from STEs to Mn^(2+)dopants in Mn^(2+)-doped halide NCs and lays the groundwork for modifying the luminescence of other metal halide perovskite NCs.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.62125402 and 62321166653).
文摘Ternary metal halides based on Cu(I)and Ag(I)have attracted intensive attention in optoelectronic applications due to their excellent luminescent properties,low toxicity,and robust stability.While the self-trapped excitons(STEs)emission mechanisms of Cu(I)halides are well understood,the STEs in Ag(I)halides remain less thoroughly explored.This study explores the STE emission efficiency within the A_(2)AgX_(3)(A=Rb,Cs;X=Cl,Br,I)system by identifying three distinct STE states in each material and calculating their configuration coordinate diagrams.We find that the STE emission efficiency in this system is mainly determined by STE stability and influenced by self-trapping and quenching barriers.Moreover,we investigate the impact of structural compactness on emission efficiency and find that the excessive electron–phonon coupling in this system can be reduced by increasing the structural compactness.The atomic packing factor is identified as a low-cost and effective descriptor for predicting STE emission efficiency in both Cs_(2)AgX_(3) and Rb_(2)AgX_(3) systems.These findings can deepen our understanding of STE behavior in metal halide materials and offer valuable insights for the design of efficient STE luminescent materials.The datasets presented in this paper are openly available in Science Data Bank at https://doi.org/10.57760/sciencedb.12094.
基金supported by the financial aid from the National Natural Science Foundation of China (No. 22271273)International Partnership Program of Chinese Academy of Sciences (No. 121522KYSB20190022)。
文摘Self-trapping excitons(STEs) emission in metal halides has been a matter of interest, correlating with the strength of electron-phonon coupling in the lattice, which are usually caused by ions with ns~2 electronic structure. In this work, Sb^(3+)/Te^(4+)ions doped Zn-based halide single crystals(SCs) with two STEs emissions have been synthesized and the possibility of its anti-counterfeiting application was explored.Further, the relationship between the strength of electron-phonon coupling and photoluminescence quantum yields(PLQYs) for STEs in a series of metal halides has been studied. And the semi-empirical range of the Huang-Rhys factors(S) for metal halides with excellent photoluminescence(PL) property has been summarized. This work provides ideas for further research into the relationship between luminescence performance and electron-phonon coupling of metal halides, and also provides a reference for designing the metal halides with high PLQYs.
基金supported by Natural Science Foundation of Jiangsu Province,Major Project(BK20222007).
文摘Two-dimensional(2D)chiral halide perovskites(CHPs)have attracted broad interest due to their distinct spin-dependent properties and promising applications in chiroptics and spintronics.Here,we report a new type of 2D CHP single crystals,namely R/S-3BrMBA_(2)PbBr_(4).The chirality of the as-prepared samples is confirmed by exploiting circular dichroism spectroscopy,indicating a successful chirality transfer from chiral organic cations to their inorganic perovskite sublattices.Furthermore,we observed bright photoluminescence spanning from 380 to 750 nm in R/S-3BrMBA_(2)PbBr_(4)crystals at room temperature.Such broad photoluminescence originates from free excitons and self-trapped excitons.In addition,efficient second-harmonic generation(SHG)performance was observed in chiral perovskite single crystals with high circular polarization ratios and non-linear optical circular dichroism.This demonstrates that R/S-3BrMBA_(2)PbBr_(4)crystals can be used to detect and generate left-and righthanded circularly polarized light.Our study provides a new platform to develop high-performance chiroptical and spintronic devices.
基金supported by the National Key R&D Program of China(2016YFB070700702)the National Natural Science Foundation of China(51761145048)+1 种基金the Fundamental Research Funds for the Central Universities(HUST:2019421JYCXJJ004)the China Postdoctoral Science Foundation Grant(2019M662624).
文摘Light-emitting diodes based on lead halide perovskite have attracted great attention due to their outstanding performance.However,their application is plagued by the toxicity of Pb and the poor stability.Herein novel copper-based all inorganic perovskite CsCu2I3 with much enhanced stability has been reported with a potential photoluminescence quantum yield(PLQY)over 20%and self-trapped excitons(STE).By taking advantage of its extraordinary thermal stability,we successfully fabricate high-quality CsCu2I3 film through direct vacuum-based deposition(VBD)of CsCu2I3 powder.The resulting film shows almost the same PLQY with the synthesized powder,as well as excellent uniformity and stability.The perovskite light-emitting diodes(Pe-LED)based on the evaporated CsCu2I3 emitting layer achieve a luminescence of 10 cd/m2 and an external quantum efficiency(EQE)of 0.02%.To the best of our knowledge,this is the first CsCu2I3 Pe-LED fabricated by VBD with STE property,which offers a new avenue for lead-free Pe-LED.
基金Scientific and Technological Bases and Talents of Guangxi(Nos.Guike AD23026119,AD21238027)the Guangxi National Science Fundation Project(No.2020GXNSFDA238004)the“Guangxi Bagui Scholars”foundation for financial support。
文摘Rare earth ions(RE^(3+))-doped double perovskites have attracted tremendous attention for its fascinating optical properties.Nevertheless,RE^(3+)generally exhibits poor photoluminescence quantum yield(PLQY)for their parity-forbidden 4f-4f transition and the low doping concentration.Herein,we reported Sb^(3+)/Sm^(3+)-codoped rare earth-based double perovskite Cs_(2)Na Lu Cl_(6)that enables efficient visible and nearinfrared(NIR)emission,which stems from self-trapped exciton(STE)and Sm^(3+),respectively.Benefit from up to 72.89%energy transfer efficiency from STE to Sm^(3+)and high doping concentrations due to similar ionic activity between Sm^(3+)and Lu^(3+),thus eruptive PLQY of 74.58%in the visible light region and 23.12%in the NIR light region can be obtained.Moreover,Sb^(3+)/Sm^(3+)-codoped Cs_(2)Na Lu Cl_(6)exhibits tunable emission characteristic in the visible light region under different excitation wavelengths,which can change from blue emission(254 nm excitation)to white emission(365 nm excitation).More particularly,only the NIR emission can be captured by the NIR camera when a 700 nm cutoff filter is added.The excellent stability and unique optical properties of Sb^(3+)/Sm^(3+)-codoped Cs_(2)Na Lu Cl_(6)enable us to demonstrate its applications in NIR light-emitting diode,triple-mode fluorescence anti-counterfeiting and information encryption.These findings provide new inspiration for the application of rare earth-based double perovskite in optoelectronic devices.
基金supported by the National Funds for Distinguished Young Scientists(No.61825503)the National Natural Science Foundation of China(Nos.62288102,62375142,22161160318).
文摘Recently,organic-inorganic hybrid metal halides(HMHs)have attracted extensive attention as promis-ing multifunctional materials by virtue of their structural diversity and tunable photophysical properties.However,it remains a challenge to design HMHs with specific functions on demand.Herein,by introduc-ing R/S-methylbenzylamine(R/S-MBA)and doping Sb^(3+),we have achieved both second harmonic gen-eration(SHG)and circularly polarized luminescence(CPL)properties in lead-free indium halides.The introduction of chiral organic cations can break the symmetry and induce the indium halides to crys-tallize in the chiral space group.The Sb^(3+)with ns2 electronic configuration can serve as the dopants to promote the formation of self-trapped excitons,so as to activate highly efficient luminescence.As a re-sult,the as-prepared Sb3+doped(R/S-MBA)3 InCl6 show not only SHG responses but also CPL signals with luminescence dissymmetry factor of−5.3×10^(−3) and 4.7×10^(−3).This work provides a new inspiration for the exploitation of chiral multifunctional materials.
基金supported by the National Natural Science Foundation of China(No.22173090 and No.91950207)the Innovation Program for Quantum Science and Technology(No.2021ZD0303303)+2 种基金the National Key Research and Development Program of China(No.2016YFA0200602 and No.2018YFA0208702)the Anhui Initiative in Quantum Information Technologies(No.AHY090200)the USTC Key Directions Project Incubation Fund(No.WK2340000106).
文摘We report a mechanistic study of excitonic photoluminescence in predesigned hybrid organic-inorganic perovskite(HOIP)systems,i.e.,(DMAEA)Pb_(2)I_(6),(DMAPA)PbI_(4),(DEAEA)Pb_(2)I_(6),and(DEAPA)_(4)Pb_(5)I_(18),featuring targeted regulation of organic cations.Starting from the prototype DMAEA(i.e.,2-N,N-dimethylamino-l-ethylamine)for(DMAEA)Pb_(2)I_(6),the other three HOIPs differ only in the extensions with CH_(2)group(s)at the“head”or/and“tail”of DMAEA that is an“alkylated ammonia”.Their crystal structures are constructed and structural distortions are evaluated.The steady-state/transient absorption and emission spectroscopic characterizations,combined with the band-structure calculations,are conducted.The two different photoluminescence(PL)mechanisms are identified,i.e.,PL emissions dominated by free excitons for(DMAPA)PbI_(4)and by self-trapped excitons for(DMAEA)Pb_(2)I_(6),(DEAEA)Pb_(2)I_(6),and(DEAPA)_(4)Pb_(5)I_(18).The self-trapped excitonic effect involved in the latter three HOIPs is quantitatively analyzed.This work would be of guiding value for the design of HOIP systems based on organic-cation engineering,beneficial for the pertinent performance optimization in light-emitting applications.
基金financially supported by the National Ten Thousand Talent Program for Young Top-notch TalentNational Natural Science Foundation of China (22379044 and 52203330)+8 种基金Shanghai Pilot Program for Basic Research (22TQ1400100-5)“Dawn”Program of Shanghai Education Commission (22SG28)Shanghai Municipal Natural Science Foundation (22ZR1418000)Shanghai Sailing Program(22YF1410000)Postdoctoral Research Foundation of China(2021M701190)Fundamental Research Funds for the Central Universities (JKD01241607 and JKVD1241041)Major Science and Technology Projects of Inner Mongolia Autonomous Region (2021ZD0042)Shanghai Engineering Research Center of Hierarchical Nanomaterials(18DZ2252400)Shanghai Frontiers Science Center of Optogenetic Techniques for Cell Metabolism。
文摘Zero-dimensional perovskite materials,characterized by broadband emission caused by self-trapped excitons,are promising materials for stimuli-responsive and photo-writeable encryption.However,existing research is focused on the effects of structural phase transitions on photophysical properties,and lacks in-depth understanding of the mechanisms of self-trapped excitons emission.Here,we demonstrate that the dehydration reaction in zero-dimensional antimony halide clusters significantly enhances the self-trapped excitons emission without inducing structural phase transition,resulting in a substantial increase in photoluminescence(PL)quantum yield from 3.5%to 91.4%.In-situ X-ray diffraction and PL techniques were employed to shed light on the relationship between the crystal structure and radiative recombination,demonstrating the introduction of rich lattice distortion during the dehydration process.Temperature-dependent PL spectra and transient absorption spectra suggest that the lattice distortion causes the moderate electron-phonon coupling strength and high exciton binding energy,facilitating self-trapped excitons to relax from the non-radiative recombination singlet state to the radiative recombination triplet state,corresponding to the enhanced emission intensity.As a proof of concept,several switchable PL applications have been established in scenarios such as anti-counterfeiting,rewritable luminescent paper,and humidity sensing.This finding elucidates the emission mechanism of self-trapped excitons and provides a novel avenue for designing switchable luminescent materials.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.10774120 and 10975114)the Natural Science Foundation of Gansu Province of China (Grant No.1010RJZA012)the Natural Science Foundation of Northwest Normal University of China (Grant No.NWNU-KJCXGC-03-48)
文摘The impurity-induced localization of two-component Bose-Einstein condensates loaded into deep one-dimensional optical lattices is studied both analytically and numerically. It is shown that, the analytical criteria for self-trapping and moving soliton/breather of the primary-component condensate are modified significantly by an admixture of an impurity component （the second component）. The realization of the self-trapped state and the moving soliton/breather states of the primary-component becomes more easy with the minor admixture of the impurity-component, even if the two components are partly overlapped.
