Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

四川师范大学学报:自然科学版

变形的一维半满t-J⊥-Jz-V模型的量子相图研究

林二印, 丁汉芹, Jun Zhang

Published Jan 1, 2016• 0 citations
OpenAlex

Abstract

借助于变形玻色算符手段、费米-玻色转化技术及重整化技术,研究了在依赖自旋的最近邻磁交换作用下,一维半满t-J扩展模型(t-J⊥-Jz-V)的弱耦合量子相图.相图显示,来自最近邻格点间各向向异性自旋交换作用(J⊥-Jz)和库仑斥力作用(V)的相互竞争使得此扩展模型基态总呈现绝缘密度波的关联行为,并且此模型量子相图的拓扑结构可通过特征参数(V/tδ^2)c=4/π来刻画,这里参数δ∈(0,1]表征玻色算符形变程度.一旦甩掉作用V(较弱的库仑作用,以致可略去),此模型基态则会呈现绝缘相向金属相间的转变.有望此结果能为理解一维强关联t-J系统及其扩展提供了一种图景和参考.

Related papers

二能级原子系综的自旋压缩

永椿 刘, 光日 金

推导二能级原子系综自旋压缩的一般理论, 给出了计算自旋压缩系数的普遍方法. 作为例子, 在推广的单轴扭曲模型中研究失谐量δ和初始自旋相干态|θ0,Φ0>的极角θ0对自旋压缩效应的影响. 结果表明, 对任意δ和Φ0, 当Φ0=Π/2时, 回到理想单轴扭曲模型的结果. 但当θ0略微偏离Π/2时, 涨落(V_)min≈N2/3, 大于理想情况下的N1/3. 最大压缩时间满足标度率N-5/6. 得到了(V_)min和tmin的解析表达式, 结果与数值模拟符合.

Zhongguo kexue. Wulixue Lixue Tianwenxue•Feb 1, 2010•0 citations

One-Dimensional Anisotropic Heisenberg Model at Finite Temperatures

Minoru Takahashi, Masuo Suzuki

The thermodynamics of the one-dimensional Heisenberg-Ising model for |Δ| ≪ 1 as well as of the X-Y-Z model is reduced to a set of non-linear integral equations under some plausible assumptions. It is remarkable that the number of unknown functions involved in them becomes finite when π/ cos -1Δ is a rational number for the Heisenberg-Ising model and when Kl /ζ is a rational number for the X-Y-Z model (where coupling constants Jx, Jy and Jz are parametrized by ζ, l, and Jz as Jx = Jz cn(2ζ, l) and Jy = Jz dn(2ζ, l); 1 ≥l ≥0, Kl ≥2ζ≥0 and Kl is the complete elliptic integral of the first kind of modulus l). The validity of our theory has been confirmed by the high-temperature expansion of the free energy through the second term for a general value of Δ and through the fourth them for Δ= ½.

Progress of Theoretical Physics•Dec 1, 1972•403 citations

周期性边界条件的一维t-J-V模型的精确解

马青山, Jun Zhang

低维材料现在已经成为凝聚态物理研究领域中最能引起学者关注的方向之一,也是研究一维可积模型的动力源泉,而t-J模型是研究强关联电子系统的典型模型,也是低维材料中最典型的模型,本文中将研究t-J模型的扩展模型t-J-V模型的可积性条件,并且得到了当J=2,V=-1/2时以及J=-2,V=-3/2时模型是可积的,是可以严格求解的.

新疆大学学报:自然科学版•Jan 1, 2010•0 citations

Low-Temperature Specific Heat of Spin-1/2 Anisotropic Heisenberg Ring

Makoto Konagai Takahashi

Low-temperature specific heat of Heisenberg-Ising ring at | Δ| ≪ 1 is calculated by the method of non-linear integral equations. Specific heat in constant magnetic field (CH) is proportional to temperature (T) at |2µ0H| ≪ (1+Δ)J. In particular lim H →0 lim T →0CH/T is 2θ/(3Jsin θ) where θ= cos -1Δ, ≤θ≪ π. It is conjectured that lim T→0 lim H→0CH/T = lim H→0 lim T→0CH/T from the result of numerical calculation. Low-temperature specific heat of the one-dimensional X-Y-Z model is proportional to T-3/2 exp (-α/T) in the case of Jz > Jy > 0, Jy ≧Jx > -Jy.

Progress of Theoretical Physics•Nov 1, 1973•137 citations

三分之一填充下的一维t-U-V-J模型的量子相图

伊尔夏提·阿斯哈尔, 丁汉芹, Jun Zhang

我们在弱耦合区域研究了一维电子体系,其中电子浓度为三分之一,相互作用包括电子的在位作用、最近邻库仑作用和自旋交换作用.玻色化方法和重整化分析预测了量子相变的发生.通过计算关联函数我们确定了量子相态.基态相图由电荷密度波、自旋密度波、三重超导态和单重超导态组成.研究结果对一维扩展赫伯德模型有着更进一步的理解.

新疆大学学报:自然科学版•Jan 1, 2016•0 citations

Correlation inequalities and phase transition in the generalized X-Y model

Masuo Suzuki

Correlation inequalities <σAz>≥0, <σAzσBz>≥<σAz><σBz>, ∂<σAz>/∂JBz≥0, and ∂<σAz>/∂JBx≤0 are proved for the generalized X-Y model with the Hamiltonian of the form H=−Σ(JAzσAz+JAxσAx), where σAz=ΠjεAσjz, σAx=ΠjεAσjx, JAz≥0,JAx≥0, A denotes an arbitrary subset of the N lattice points, and σjx, σjz are the Pauli matrices. This yields a simple extension of the Griffiths-Kelly-Sherman inequalities to the above quantal system. Applications to phase transitions are also discussed briefly.

Journal of Mathematical Physics•Jul 1, 1973•10 citations
借助于变形玻色算符手段、费米-玻色转化技术及重整化技术,研究了在依赖自旋的最近邻磁交换作用下,一维半满t-J扩展模型(t-J⊥-Jz-V)的弱耦合量子相图.相图显示,来自最近邻格点间各向向异性自旋交换作用(J⊥-Jz)和库仑斥力作用(V)的相互竞争使得此扩展模型基态总呈现绝缘密度波的关联行为,并且此模型量子相图的拓扑结构可通过特征参数(V/tδ^2)c=4/π来刻画,这里参数δ∈(0,1]表征玻色算符形变程度.一旦甩掉作用V(较弱的库仑作用,以致可略去),此模型基态则会呈现绝缘相向金属相间的转变.有望此结果能为理解一维强关联t-J系统及其扩展提供了一种图景和参考.
推导二能级原子系综自旋压缩的一般理论, 给出了计算自旋压缩系数的普遍方法. 作为例子, 在推广的单轴扭曲模型中研究失谐量δ和初始自旋相干态|θ0,Φ0>的极角θ0对自旋压缩效应的影响. 结果表明, 对任意δ和Φ0, 当Φ0=Π/2时, 回到理想单轴扭曲模型的结果. 但当θ0略微偏离Π/2时, 涨落(V_)min≈N2/3, 大于理想情况下的N1/3. 最大压缩时间满足标度率N-5/6. 得到了(V_)min和tmin的解析表达式, 结果与数值模拟符合.
The thermodynamics of the one-dimensional Heisenberg-Ising model for |Δ| ≪ 1 as well as of the X-Y-Z model is reduced to a set of non-linear integral equations under some plausible assumptions. It is remarkable that the number of unknown functions involved in them becomes finite when π/ cos -1Δ is a rational number for the Heisenberg-Ising model and when Kl /ζ is a rational number for the X-Y-Z model (where coupling constants Jx, Jy and Jz are parametrized by ζ, l, and Jz as Jx = Jz cn(2ζ, l) and Jy = Jz dn(2ζ, l); 1 ≥l ≥0, Kl ≥2ζ≥0 and Kl is the complete elliptic integral of the first kind of modulus l). The validity of our theory has been confirmed by the high-temperature expansion of the free energy through the second term for a general value of Δ and through the fourth them for Δ= ½.
Low-temperature specific heat of Heisenberg-Ising ring at | Δ| ≪ 1 is calculated by the method of non-linear integral equations. Specific heat in constant magnetic field (CH) is proportional to temperature (T) at |2µ0H| ≪ (1+Δ)J. In particular lim H →0 lim T →0CH/T is 2θ/(3Jsin θ) where θ= cos -1Δ, ≤θ≪ π. It is conjectured that lim T→0 lim H→0CH/T = lim H→0 lim T→0CH/T from the result of numerical calculation. Low-temperature specific heat of the one-dimensional X-Y-Z model is proportional to T-3/2 exp (-α/T) in the case of Jz > Jy > 0, Jy ≧Jx > -Jy.
Correlation inequalities <σAz>≥0, <σAzσBz>≥<σAz><σBz>, ∂<σAz>/∂JBz≥0, and ∂<σAz>/∂JBx≤0 are proved for the generalized X-Y model with the Hamiltonian of the form H=−Σ(JAzσAz+JAxσAx), where σAz=ΠjεAσjz, σAx=ΠjεAσjx, JAz≥0,JAx≥0, A denotes an arbitrary subset of the N lattice points, and σjx, σjz are the Pauli matrices. This yields a simple extension of the Griffiths-Kelly-Sherman inequalities to the above quantal system. Applications to phase transitions are also discussed briefly.