期刊文献+
共找到141篇文章
< 1 2 8 >
每页显示 20 50 100
Pairing correlation of the kagome-lattice Hubbard model with the nearest-neighbor interaction
1
作者 Chen Yang Chao Chen +2 位作者 Runyu Ma Ying Liang Tianxing Ma 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第10期41-45,共5页
A recently discovered family of kagome lattice materials,AV_(3)Sb_(5)(A=K,Rb,Cs),has attracted great interest,especiallyin the debate over their dominant superconducting pairing symmetry.To explore this issue,we study... A recently discovered family of kagome lattice materials,AV_(3)Sb_(5)(A=K,Rb,Cs),has attracted great interest,especiallyin the debate over their dominant superconducting pairing symmetry.To explore this issue,we study the superconductingpairing behavior within the kagome-lattice Hubbard model through the constrained path Monte Carlo method.It isfound that doping around the Dirac point generates a dominant next-nearest-neighbor-d pairing symmetry driven by on-siteCoulomb interaction U.However,when considering the nearest-neighbor interaction V,it may induce nearest-neighbor-ppairing to become the preferred pairing symmetry.Our results provide useful information to identify the dominant superconductingpairing symmetry in the AV_(3)Sb_(5)family. 展开更多
关键词 kagome-lattice hubbard model SUPERCONDUCTIVITY pairing symmetry CPMC
原文传递
Entanglement and thermalization in the extended Bose–Hubbard model after a quantum quench: A correlation analysis
2
作者 苏晓强 许宗菊 赵有权 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第2期168-174,共7页
Exploring the role of entanglement in quantum nonequilibrium dynamics is important to understand the mechanism of thermalization in an isolated system. We study the relaxation dynamics in a one-dimensional extended B... Exploring the role of entanglement in quantum nonequilibrium dynamics is important to understand the mechanism of thermalization in an isolated system. We study the relaxation dynamics in a one-dimensional extended Bose–Hubbard model after a global interaction quench by considering several observables: the local Boson numbers, the nonlocal entanglement entropy, and the momentum distribution functions. We calculate the thermalization fidelity for different quench parameters and different sizes of subsystems, and the results show that the degree of thermalization is affected by the distance from the integrable point and the size of the subsystem. We employ the Pearson coefficient as the measurement of the correlation between the entanglement entropy and thermalization fidelity, and a strong correlation is demonstrated for the quenched system. 展开更多
关键词 quantum quench quantum entanglement THERMALIZATION extended Bose–hubbard model
原文传递
Four-Electron Systems in the Impurity Hubbard Model. Second Triplet State. Spectra of the System in the ν-Dimensional Lattice Zν
3
作者 S. M. Tashpulatov R. T. Parmanova 《Journal of Applied Mathematics and Physics》 2023年第11期3393-3427,共35页
We consider an energy operator of four-electron system in the Impurity Hubbard model with a coupling between nearest-neighbors. The spectrum of the systems in the second triplet state in a ν-dimensional lattice is in... We consider an energy operator of four-electron system in the Impurity Hubbard model with a coupling between nearest-neighbors. The spectrum of the systems in the second triplet state in a ν-dimensional lattice is investigated. For investigation the structure of essential spectra and discrete spectrum of the energy operator of four-electron systems in an impurity Hubbard model, for which the momentum representation is convenient. In addition, we used the tensor products of Hilbert spaces and tensor products of operators in Hilbert spaces and described the structure of essential spectrum and discrete spectrum of the energy operator of four-electron systems in an impurity Hubbard model for the second triplet state of the system. The investigations show that the essential spectrum of the system consists of the union of no more than sixteen segments, and the discrete spectrum of the system consists of no more than eleven eigenvalues. 展开更多
关键词 Spectra of Four-Electron System Bound State Anti-Bound State Impurity hubbard model Quintet State Singlet State Triplet State
下载PDF
Functional Integrals and Excitation Energy in Three-Band Hubbard Model 被引量:4
4
作者 YAN Jun 《Communications in Theoretical Physics》 SCIE CAS CSCD 2008年第3期567-570,共4页
The normal and anomalous Green's functions of antiferromagnetie state in three-band Hubbard model are studied by using functional integrals and temperature Green's function method. The equations of energy spectrum a... The normal and anomalous Green's functions of antiferromagnetie state in three-band Hubbard model are studied by using functional integrals and temperature Green's function method. The equations of energy spectrum are derived. In addition, excitation energy of Fermi fields are calculated under long wave approximation. 展开更多
关键词 functional integrals Green's functions excitation energy hubbard model
下载PDF
The Structure of Essential Spectra and Discrete Spectrum of Three-Electron Systems in the Impurity Hubbard Model—Quartet State 被引量:3
5
作者 S. M. Tashpulatov 《Journal of Applied Mathematics and Physics》 2021年第6期1391-1421,共31页
We consider a three-electron system in the Impurity Hubbard model with a coupling between nearest-neighbors. Our research aim consists of studying the structure of essential spectrum and discrete spectra of the energy... We consider a three-electron system in the Impurity Hubbard model with a coupling between nearest-neighbors. Our research aim consists of studying the structure of essential spectrum and discrete spectra of the energy operator of three-electron systems in the impurity Hubbard model in the quartet state of the system in a <em>v</em>-dimensional lattice. We have reduced the study of the spectrum of the three-electron quartet state operator in the impurity Hubbard model to the study of the spectrum of a simpler operator. We proved the essential spectra of the three-electron systems in the Impurity Hubbard model in the quartet state is the union of no more than six segments, and the discrete spectrum of the system is consists of no more than four eigenvalues. 展开更多
关键词 Essential Spectrum Discrete Spectrum Three-Electron System Local Impurity States Impurity hubbard model Quartet State Doublet State
下载PDF
Multiferroic phase transitions in manganites RMnO_3:A two-orbital double exchange simulation 被引量:1
6
作者 陶永梅 林林 +1 位作者 董帅 刘俊明 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第10期456-461,共6页
The semi-quantum two-orbital exchange model is used to investigate the effect of small rare-earth ion substitution on orthorhombic RMnO 3 with A-type antiferromagnetic order,using the Monte Carlo algorithm,exact diago... The semi-quantum two-orbital exchange model is used to investigate the effect of small rare-earth ion substitution on orthorhombic RMnO 3 with A-type antiferromagnetic order,using the Monte Carlo algorithm,exact diagonalization,and zero-temperature optimization approaches.It is revealed that the substitution results in a rich multiferroic phase diagram where the coexisting A-type antiferromagnetic phase and spiral spin phase,pure spiral spin phase,coexisting spiral spin phase,the E-type antiferromagnetic phase,and the pure E-type antiferromagnetic phase emerge in sequence.The multiferroic phase transitions modulate substantially the electric polarization,which is consistent qualitatively with recent experiments. 展开更多
关键词 multiferroic phase R-site doping two-orbital exchange model
原文传递
Drude Weight, Optical Conductivity of Two-Dimensional Hubbard Model at Half Filling 被引量:1
7
作者 XU Lei ZHANG Jun 《Communications in Theoretical Physics》 SCIE CAS CSCD 2008年第7期237-242,共6页
We study the Drude weight D and optical conductivity of the two-dimensional (2D) Hubbard model at half filling with staggered magnetic flux (SMF). When SMF being introduced, the hopping integrals are modulated by ... We study the Drude weight D and optical conductivity of the two-dimensional (2D) Hubbard model at half filling with staggered magnetic flux (SMF). When SMF being introduced, the hopping integrals are modulated by the magnetic flux. The optical sum rule, which is related to the mean kinetic energy of band electrons, is evaluated for this 2D Hubbard Hamiltonian. Our present result gives the dependence of the kinetic energy, D and the optical conductivity on SMF and U. At half filling D vanishes exponentially with system size. We also find in the frequency dependence of the optical conductivity, there is δ-function peak at ω ≈ 2|m|U and the incoherent excitations begin to present themselves extended to a higher energy region. 展开更多
关键词 Drude weight optical conductivity hubbard model
下载PDF
Structure of Essential Spectrum and Discrete Spectra of the Energy Operator of Five-Electron Systems in the Hubbard Model. Third and Fourth Doublet States 被引量:1
8
作者 S. M. Tashpulatov 《Journal of Applied Mathematics and Physics》 2020年第12期2886-2918,共33页
We consider a five-electron system in the Hubbard model with a coupling between nearest-neighbors. The structure of essential spectrum and discrete spectrum of the systems in the third and fourth doublet states in a &... We consider a five-electron system in the Hubbard model with a coupling between nearest-neighbors. The structure of essential spectrum and discrete spectrum of the systems in the third and fourth doublet states in a <em>v</em>-dimensional lattice is investigated. We prove that the essential spectrum of the system in a third doublet state consists is the union of at most four segments, and discrete spectrum of the system is empty. We show that the essential spectrum of the system in a fourth doublet state consists of the union of at most seven segments, and discrete spectrum of the system consists of no more than one point. 展开更多
关键词 Essential Spectrum Discrete Spectrum Five-Electron System Bound State Anti-Bound State hubbard model Doublet State Sextet State Quartet State
下载PDF
Spectra of the Energy Operator of Two-Electron System in the Impurity Hubbard Model 被引量:1
9
作者 Sa’dulla Tashpulatov 《Journal of Applied Mathematics and Physics》 2022年第9期2743-2779,共37页
We consider two-electron systems for the impurity Hubbard Model and investigate the spectrum of the system in a singlet state for the v-dimensional integer valued lattice Z<sup>v</sup>. We proved the essen... We consider two-electron systems for the impurity Hubbard Model and investigate the spectrum of the system in a singlet state for the v-dimensional integer valued lattice Z<sup>v</sup>. We proved the essential spectrum of the system in the singlet state is consists of union of no more then three intervals, and the discrete spectrum of the system in the singlet state is consists of no more then five eigenvalues. We show that the discrete spectrum of the system in the triplet and singlet states differ from each other. In the singlet state the appear additional two eigenvalues. In the triplet state the discrete spectrum of the system can be empty set, or is consists of one-eigenvalue, or is consists of two eigenvalues, or is consists of three eigenvalues. For investigation the structure of essential spectra and discrete spectrum of the energy operator of two-electron systems in an impurity Hubbard model, for which the momentum representation is convenient. In addition, we used the tensor products of Hilbert spaces and tensor products of operators in Hilbert spaces and described the structure of essential spectrum and discrete spectrum of the energy operator of two-electron systems in an impurity Hubbard model. 展开更多
关键词 Two-Electron System Impurity hubbard model Singlet State Triplet State Essential Spectra Discrete Spectrum
下载PDF
Spectra of the Energy Operator of Four-Electron Systems in the Impurity Hubbard Model. Triplet State 被引量:1
10
作者 S. M. Tashpulatov R. T. Parmanova 《Journal of Applied Mathematics and Physics》 2021年第11期2776-2795,共20页
We consider the energy operator of four-electron systems in an impurity Hubbard model and investigated the structure of essential spectra and discrete spectrum of the system in the first triplet state in a one-dimensi... We consider the energy operator of four-electron systems in an impurity Hubbard model and investigated the structure of essential spectra and discrete spectrum of the system in the first triplet state in a one-dimensional lattice. For investigation the structure of essential spectra and discrete spectrum of the energy operator of four-electron systems in an impurity Hubbard model, for which the momentum representation is convenient. In addition, we used the tensor products of Hilbert spaces and tensor products of operators in Hilbert spaces and described the structure of essential spectrum and discrete spectrum of the energy operator of four-electron systems in an impurity Hubbard model. The investigations show that there are such cases: 1) the essential spectrum of the system consists of the union of no more than eight segments, and the discrete spectrum of the system consists of no more than three eigenvalues;2) the essential spectrum of the system consists of the union of no more than sixteen segments, and the discrete spectrum of the system consists of no more than eleven eigenvalues;3) the essential spectrum of the system consists of the union of no more than three segments, and the discrete spectrum of the system is the empty set. Consequently, the essential spectrum of the system consists of the union of no more than sixteen segments, and the discrete spectrum of the system consists of no more than eleven eigenvalues. 展开更多
关键词 hubbard model Essential Spectrum Discrete Spectrum Four Electron Systems Quintet State Triplet State Singlet State SPECTRA
下载PDF
Hubbard model on an anisotropic checkerboard lattice at finite temperatures: Magnetic and metal–insulator transitions
11
作者 Hai-Di Liu 《Chinese Physics B》 SCIE EI CAS CSCD 2019年第10期498-503,共6页
We study magnetic and Mott transitions of the Hubbard model on the geometrically frustrated anisotropic checkerboard lattice at half filling using cellular dynamical mean-field theory. Phase diagrams over a wide area ... We study magnetic and Mott transitions of the Hubbard model on the geometrically frustrated anisotropic checkerboard lattice at half filling using cellular dynamical mean-field theory. Phase diagrams over a wide area of the parameter space are obtained by varying the interparticle interaction strength, geometric frustration strength, and temperature. Our results show that frustration and thermal fluctuations play a competing role against the interactions and in general favor a metallic phase without antiferromagnetic order. Due to their interplay, the system exhibits competition between antiferromagnetic insulator, antiferromagnetic metal, paramagnetic insulator, and paramagnetic metal phases in the intermediateinteraction regime. In the strong-interaction limit, which reduces to the Heisenberg model, our result is consistent with previous studies. 展开更多
关键词 GEOMETRICAL FRUSTRATION CHECKERBOARD LATTICE hubbard model
原文传递
Mott transition in ruby lattice Hubbard model
12
作者 An Bao 《Chinese Physics B》 SCIE EI CAS CSCD 2019年第5期256-262,共7页
Mott transition in a ruby lattice with fermions described by the Hubbard model including on-site repulsive interaction is investigated by combining the cellular dynamical mean-field theory and the continuous-time quan... Mott transition in a ruby lattice with fermions described by the Hubbard model including on-site repulsive interaction is investigated by combining the cellular dynamical mean-field theory and the continuous-time quantum Monte Carlo algorithm. The effect of temperature and on-site repulsive interaction on the metallic–insulating phase transition in ruby lattice with fermions is discussed based on the density of states and double occupancy. In addition, the magnetic property of each phase is discussed by defining certain magnetic order parameters. Our results show that the antiferromagnetic metal is found at the low temperature and weak interaction region and the antiferromagnetic insulating phase is found at the low temperature and strong interaction region. The paramagnetic metal appears in whole on-site repulsive interaction region when the temperature is higher than a certain value and the paramagnetic insulator appears at the middle scale of temperature and on-site repulsive interaction. 展开更多
关键词 MOTT transition RUBY LATTICE hubbard model cellular dynamical MEAN-FIELD theory
原文传递
Slater determinant and exact eigenstates of the two-dimensional Fermi–Hubbard model
13
作者 Jun-Hang Ren Ming-Yong Ye Xiu-Min Lin 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第7期264-267,共4页
We consider the construction of exact eigenstates of the two-dimensional Fermi-Hubbard model defined on an L ×L lattice with a periodic condition. Based on the characteristics of Slater determinants, several meth... We consider the construction of exact eigenstates of the two-dimensional Fermi-Hubbard model defined on an L ×L lattice with a periodic condition. Based on the characteristics of Slater determinants, several methods are introduced to construct exact eigenstates of the model. The eigenstates constructed are independent of the on-site electron interaction and some of them can also represent exact eigenstates of the two-dimensional Bose-Hubbard model. 展开更多
关键词 hubbard model exact eigenstate Slater determinant
原文传递
Doping-driven orbital-selective Mott transition in multi-band Hubbard models with crystal field splitting
14
作者 王义林 黄理 +1 位作者 杜亮 戴希 《Chinese Physics B》 SCIE EI CAS CSCD 2016年第3期16-21,共6页
We have studied the doping-driven orbital-selective Mott transition in multi-band Hubbard models with equal band width in the presence of crystal field splitting. Crystal field splitting lifts one of the bands while l... We have studied the doping-driven orbital-selective Mott transition in multi-band Hubbard models with equal band width in the presence of crystal field splitting. Crystal field splitting lifts one of the bands while leaving the others degener- ate. We use single-site dynamical mean-field theory combined with continuous time quantum Monte Carlo impurity solver to calculate a phase diagram as a function of total electron filling N and crystal field splitting A. We find a large region of orbital-selective Mott phase in the phase diagram when the doping is large enough. Further analysis indicates that the large region of orbital-selective Mott phase is driven and stabilized by doping. Such models may account for the orbital-selective Mott transition in some doped realistic strongly correlated materials. 展开更多
关键词 orbital-selective Mott transition DOPING multi-band hubbard model
原文传递
The Critical Properties of One—Dimensional Extended Hubbard Model
15
作者 WANGZhi-Guo ZHANGYu-Mei 《Communications in Theoretical Physics》 SCIE CAS CSCD 2002年第2期237-242,共6页
In the framework of nonperturbative quantum field theory, the critical phenomena of one-dimensionalextended Hubbard model (EHM) at half-filling are discussed from weak to intermediate interactions. After the EHMbeing ... In the framework of nonperturbative quantum field theory, the critical phenomena of one-dimensionalextended Hubbard model (EHM) at half-filling are discussed from weak to intermediate interactions. After the EHMbeing mapped into two decoupled sine-Gordon models, the ground state phase diagram of the system is derived in anexplicit way. It is confirmed that the coexisting phases appear in different interaction regimes which cannot be foundby conventional theoretical methods. The diagram shows that there are seven different phase regions in the groundstate, which seems not to be the same as previous discussions, especially the boundary between the phase separationand condensed phase regions. The phase transition properties of the model between various phase regions are studied indetail. 展开更多
关键词 one-dimensional extended hubbard model BOSONIZATION phase diagram coexisting phase
下载PDF
Supersolid Phase in One-Dimensional Hard-Core Boson Hubbard Model with a Superlattice Potential
16
作者 GUO Huai-Ming LIANG Ying 《Communications in Theoretical Physics》 SCIE CAS CSCD 2008年第11期1142-1144,共3页
The ground state of the one-dimensional hard-core boson Hubbard model with a superlattice potential is studied by quantum Monte Carlo methods. We demonstrate that besides the CDW phase and the Mott insulator phase, th... The ground state of the one-dimensional hard-core boson Hubbard model with a superlattice potential is studied by quantum Monte Carlo methods. We demonstrate that besides the CDW phase and the Mott insulator phase, the supersolid phase emerges due to the presence of the superlattice potential, which reflects the competition with the hopping term. We also study the densities of sublattices and have a clear idea about the distribution of the bosons on the lattice. 展开更多
关键词 boson hubbard model quantum Monte Carlo supersolid phase
下载PDF
Fermion Coherent State Studies of One-Dimensional Hubbard Model
17
作者 LIN Ji GAO Xian-Long WANG Ke-Lin 《Communications in Theoretical Physics》 SCIE CAS CSCD 2007年第1期161-166,共6页
We present a comparative study of the ground state of the one-dimensional Hubbard model. We first use a new fermion coherent state method in the framework of Fermi liquid theory by introducing a hole operator and cons... We present a comparative study of the ground state of the one-dimensional Hubbard model. We first use a new fermion coherent state method in the framework of Fermi liquid theory by introducing a hole operator and considering the interactions of two pairs electrons and holes. We construct the ground state of the Hubbard model as |〉=[f+∑^tφk1σ1hk2σ2ck3σ3hk4σ4 ∏exp(ρck1σ1 hk2σ2)]|〉0,where φ and ρ are the coupling constants. Our results are then compared to those of varlational methods, density functional theory based on the exact solvable Bethe ansatz solutions, variational Monto-Carlo method (VMC) as well as to the exact result of the infinite system. We find satisfactory agreement between the fermion coherent state scheme and the VMC data, and provide a new picture to deal with the strongly correlated system. 展开更多
关键词 hubbard model fermion coherent state density functional theory
下载PDF
Charge Gap in One—Dimensional Extended Hubbard Model
18
作者 DINGGuo-Hui YEFei 等 《Communications in Theoretical Physics》 SCIE CAS CSCD 2003年第1期105-108,共4页
By using the bosonization and renormalization group methods, we have studied the low energy physical properties in one-dimensional extended Hubbard model. The formation of charge and spin gaps is investigated at the h... By using the bosonization and renormalization group methods, we have studied the low energy physical properties in one-dimensional extended Hubbard model. The formation of charge and spin gaps is investigated at the half-filled electron band. An analytical expression for the charge gap in terms of the Coulomb repulsive interaction strength U and the nearest-neighbour interaction parameter V is obtained. 展开更多
关键词 extended hubbard model BOSONIZATION
下载PDF
Structure of Essential Spectra and Discrete Spectrum of the Energy Operator of Six-Electron Systems in the Hubbard Model. First Quintet and First Singlet States
19
作者 S. M. Tashpulatov 《Journal of Applied Mathematics and Physics》 2022年第11期3424-3461,共38页
We consider the energy operator of six-electron systems in the Hubbard model and investigate the structure of essential spectra and discrete spectrum of the system in the first quintet and first singlet states in the ... We consider the energy operator of six-electron systems in the Hubbard model and investigate the structure of essential spectra and discrete spectrum of the system in the first quintet and first singlet states in the v-dimensional lattice. 展开更多
关键词 hubbard model Essential Spectrum Discrete Spectrum Six Electron Systems Octet State Singlet State Quintet State
下载PDF
Itinerant Topological Magnons in SU (2) Symmetric Topological Hubbard Models with Nearly Flat Electronic Bands
20
作者 Zhao-Long Gu Jian-Xin Li 《Chinese Physics Letters》 SCIE CAS CSCD 2021年第5期132-136,共5页
We show that a suitable combination of flat-band ferromagnetism,geometry and nontrivial electronic band topology can give rise to itinerant topological magnons.An SU(2) symmetric topological Hubbard model with nearly ... We show that a suitable combination of flat-band ferromagnetism,geometry and nontrivial electronic band topology can give rise to itinerant topological magnons.An SU(2) symmetric topological Hubbard model with nearly flat electronic bands,on a Kagome lattice,is considered as the prototype.This model exhibits ferromagnetic order when the lowest electronic band is half-filled.Using the numerical exact diagonalization method with a projection onto this nearly flat band,we can obtain the magnonic spectra.In the flat-band limit,the spectra exhibit distinct dispersions with Dirac points,similar to those of free electrons with isotropic hoppings,or a local spin magnet with pure ferromagnetic Heisenberg exchanges on the same geometry.Significantly,the non-flatness of the electronic band may induce a topological gap at the Dirac points,leading to a magnonic band with a nonzero Chern number.More intriguingly,this magnonic Chern number changes its sign when the topological index of the electronic band is reversed,suggesting that the nontrivial topology of the magnonic band is related to its underlying electronic band.Our work suggests interesting directions for the further exploration of,and searches for,itinerant topological magnons. 展开更多
关键词 Itinerant Topological Magnons in SU Symmetric Topological hubbard models with Nearly Flat Electronic Bands
原文传递
上一页 1 2 8 下一页 到第
使用帮助 返回顶部