1/5掺杂反铁磁海森堡自旋链的基态  

The ground state of the 1/5-doped antiferromagntic spin chain

作　　者：陆文彬[1] 潘丽华[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）》2009年第4期26-30,共5页Journal of Yangzhou University：Natural Science Edition

基　　金：江苏省高校自然科学基金资助项目(05KJB140147)

摘　　要：利用密度矩阵重整化群方法研究1/5掺杂对自旋1/2海森堡反铁磁链的影响.研究表明,掺入侧自旋能减弱近邻自旋关联但增强长程自旋关联,同时侧自旋的掺入破坏了子格对称性,导致系统基态反铁磁和铁磁长程序共存.侧自旋对量子涨落的抑制作用随自旋关联距离的增加而减弱,且其自身受到量子涨落的影响最小.对于1/5掺杂反铁磁海森堡自旋链,量子涨落的影响明显,引起了交错磁化率47%的减弱.By density-matrix renormalization group method, the 1/5-doping effect on the spin-1/2 Heisenberg antiferromagnetic chain is investigated. It is shown that adding side spins can weaken the correlations between near-neighbor spins while strengthen those between long-range spins. Because of the broken of sublattice symmetry by side spins, the ferromagnetic and the antiferromagnetic long range orders can coexist in the ground state. Side spins can lower the quantum fluctuations, and the effect will weaken as the increasing of interaction distance. The quantum fluctuation of side spin is weakest. But for the 1/5-doped antiferromagntic chain, the quantum fluctuation leads to the 47% loss of its staggered susceptibility.

关 键 词：准一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：O443.1[理学—电磁学]