一维量子XX-ZZ模型的量子相变  

Quantum Phase Transitions of One-Dimensional XX-ZZ Model

作　　者：钟鸣[1] 刘小贤[1] 

机构地区：[1]南京师范大学物理科学与技术学院,江苏南京210097

出　　处：《南京师大学报（自然科学版）》2010年第4期58-62,共5页Journal of Nanjing Normal University(Natural Science Edition)

基　　金：江苏省高校自然科学基础研究项目(10KJB140004)

摘　　要：讨论了一维量子XX-ZZ模型的量子相变类型,数值研究了协作参量、保真度在相变点附近的行为和李-杨零点的分布情况.发现系统同时存在一级和二级相变,对应的保真度行为和李杨零点分布有所区别,但协作参量只能标识二级相变,不能显示一级相变.The quantum phase transitions of one-dimensional XX-ZZ model are discussed. The behaviors of concurrence, fidelity near the critical points and the distribution of Lee-Yang zeros are studied numerically. It is found that the behaviors of fidelity and Lee-Yang zeros can distinguish the first order and second order phase transitions. But the concurrence can only characterize the second order phase transition of this model.

关 键 词：量子XX—ZZ模型 量子相变 协作参量 保真度 李-杨零点 

分 类 号：O469[理学—凝聚态物理]