拓扑绝缘体是当前凝聚态物理领域中的一个热点问题.这类材料的典型特征是体内元激发存在能隙,但在边界上具有受拓扑保护的无能隙边缘激发.从广义上讲,拓扑绝缘体可以分两大类:一类是破坏时间反演的量子霍尔体系,另一类是新近发现的时间反演不变的拓扑绝缘体.这些新材料的奇特物理性质和潜在的应用前景,使其倍受人们关注.文章对这种新奇物态的物理性质和研究进展做了简要的介绍.
A new kind of insulator has been proposed recently,which is fully gapped in the bulk but has a metallic edge or surface states that are protected topologically.These electronic materials are dubbed as topological insulators(TIs).Generally speaking,TIs can be divided into two classes.One is the quantum Hall system which was found in the 1980s to show breaking of time reversal symmetry(TRS),and another is the newly discovered type which does not demonstrate TRS breaking and has attracted much attention recently.This article presents a brief review of recent advances in the development of TIs.