子格对称破缺的准一维海森堡系统的DMRG研究  

DMRG research on a system of quasi-one-dimensional Heisenberg antiferromagnetic chain with symmetry breaking of sublattice

作　　者：张松俊[1] 蔡卓[1] 蒋建军[1] 刘拥军[1] 

机构地区：[1]扬州大学物理科学与技术学院,江苏扬州225002

出　　处：《扬州大学学报（自然科学版）》2007年第4期31-33,共3页Journal of Yangzhou University：Natural Science Edition

基　　金：江苏省高校重大基础研究基金资助项目(05KJB14047)

摘　　要：利用密度矩阵重整化群(DMRG)方法研究一种S=1/2子格对称破缺的准一维反铁磁海森堡自旋链,计算了该系统单个原胞的基态能、自旋关联函数以及交错磁化率.研究表明:尽管自旋相互作用是反铁磁的,但由于子格对称破缺的影响,而使系统基态呈现出不饱和的铁磁性(即亚铁磁特性),这与运用LIEB-MATTIS定理的预测结果和自旋波近似的计算定性一致.By using density-matrix renormalization group （DMRG） method, the authors investigate a system of quasi-one-dimensional Heisenberg antiferromagnetic chain with symmetry breaking of sublattice. The ground state energy per unit cell, spin correlation function and staggered susceptibility are calculated. The calculations show that the system exhibits ferrimagnetic properties, although the spin-spin interactions are antiferromagnetic. The results are consistent qualitatively with the conclusion predicted by LIEB-MATTIS theorem and the results calculated by spin-wave theory.

关 键 词：准-维反铁磁海森堡自旋链 密度矩阵重整化群 自旋关联 交错磁化率 

分 类 号：O441[理学—电磁学] O413.1[理学—物理]