arXivDaily arXiv每日学术速递 周一至周五更新
北美退伍军人节(Veterans Day),12 日无更新
arXiv 1808.07779cond-mat.mes-hallcond-mat.mtrl-sci
收藏

非均匀(Pb,Sn)Se(001)表面的拓扑态

Topological states on uneven (Pb,Sn)Se (001) surfaces

Rafał Rechciński, Ryszard Buczko

摘要:

从理论上研究了拓扑晶体绝缘体表面形貌对电子结构的影响。作为一个例子,在(001)(Pb,Sn)Se表面上的原子高度的台阶的拓扑保护的电子态的结构进行了建模。在包络函数模型中,它示出谷混合,负责特殊的“双狄拉克锥”形状的表面状态分散的现象,关键取决于表面的结构。通过改变阶地中原子层的宽度和数量,对最近的实验发现,即,实现了原子奇高台阶边束缚的一维态的出现以及粗糙表面上“双狄拉克锥”结构的坍缩。这种方法也使我们能够确定表征阶地及其界面的拓扑指数。在(Pb,Sn)Se的(001)面中,相邻的阶地可以用不同的缠绕数拓扑不变量来描述。

英文摘要:

The impact of surface morphology on electronic structure of topological crystalline insulators is studied theoretically. As an example, the structure of topologically protected electronic states on a (001) (Pb,Sn)Se surface with terraces of atomic height is modeled. Within the envelope function model it is shown that valley mixing, the phenomenon responsible for the peculiar "double Dirac cone" shape of the surface state dispersion, depends crucially on the structure of the surface. By varying the width and the number of atomic layers in the terraces, a comprehensive explanation of recent experimental findings, i.e., the emergence of 1D states bound to odd-height atomic step edges as well as the collapse of "double Dirac cone" structure on a rough surface, is achieved. This approach allows us also to determine topological indices characterizing terraces and their interfaces. In the (001) surface of (Pb,Sn)Se the adjacent terraces turn out to be described by different values of the winding number topological invariant.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑