摘要
利用严格对角化和密度矩阵重整化群方法研究近邻作用为铁磁耦合、对角的次近邻自旋为反铁磁耦合的两条链的混合梳子S=1/2海森堡模型,计算了该系统的基态能和基态总自旋.结果表明:当阻挫α≤0.25时,系统基态是单纯的铁磁态;随着阻挫的增强,系统基态经历一段总自旋S≠0的倾斜相,再转变到S=0的反铁磁态;与其不同的是,在混合梯子模型中,基态从单纯的铁磁态直接转变成S=0的反铁磁态.
By using exact diagonalization method and density matrix renormalization group method, the author studies the ground states of the two-leg spin-1/2 mixed comb model, of which the nea- rest-neighbor interaction is ferromagnetic（FM） and the diagonal next-nearest-neighbor interaction is antiferromagnetic（AF）. The ground state energy and the total spin are analyzed. When α≤0.25, the ground states are simply FM. With the diagonal AF frustration increasing, the ground state transforms from FM state to a canted state region, and then to the S=0 AF state. Differently in the mixed ladder model, the ground state directly transforms from FM state to AF state.
出处
《扬州大学学报（自然科学版）》
CAS
CSCD
北大核心
2012年第3期30-34,共5页
Journal of Yangzhou University：Natural Science Edition
基金
江苏省科技支撑计划(工业)项目(BE2009106)
关键词
严格对角化
密度矩阵重整化群
反铁磁阻挫效应
海森堡模型
exact diagonalization
density matrix renormalization group
effect of anti-ferromagneticfrustration
Heisenberg model
