Z_2拓扑不变量与拓扑绝缘体  

Z_2 topological invariant and topological insulators

作　　者：余睿[1] 方忠[1] 戴希[1] 

机构地区：[1]中国科学院物理研究所,北京100190

出　　处：《物理》2011年第7期462-468,共7页Physics

基　　金：国家自然科学基金(批准号:131212503413;10821403);国家重点基础研究发展计划(批准号:2007CB925000)资助项目

摘　　要：文章回顾了几种Z2拓扑数的计算方法,并详细介绍了一种用非阿贝尔贝里联络表示绝缘体Z2不变量的计算方法.这种方法可以确定出一般能带绝缘体的拓扑性质,而不需要限定波函数的规范.利用这种新方法,文章作者计算了二维石墨烯(graphene)系统的Z2拓扑数,得到了和以前研究相一致的结论.We briefly review some of the equivalent ways of determining the Z2 invariant in 2D insulators. We introduce a new expression for this invariant in band insulators using non-Abelian Berry＇s connection. The new expression can be used to determine the topological nature of a general band insulator in a way that does not require any gauge fixing. By this means, we have recalculated the Z2 topological index for 2D graphene systems, and have obtained results consistent with previous studies.

关 键 词：非阿贝尔贝里联络 拓扑绝缘体 Z2拓扑数 

分 类 号：O469[理学—凝聚态物理]