拓扑Weyl半金属简介

Topological Weyl semimetals

材料体系的拓扑量子行为是当前凝聚态物理研究的热点。作为一种新型拓扑量子态,Weyl半金属最近引起了人们的关注。文章以烧绿石结构铱氧化物A2Ir2O7(其中A=Y或稀土元素)为例,介绍了Weyl半金属的奇特性质:Weyl点受拓扑保护稳定;Weyl半金属有着受拓扑保护的表面态,即非闭合的费米弧;Weyl半金属的反常霍尔效应与Weyl点的位置有关,和能带的细节无关;Weyl半金属特有的输运性质。文章还介绍了人们预言的几种Weyl半金属以及相关的实验进展。

Currently, the topological behavior of materials is a hot topic in condensed matter physics. As a new class of topological quantum states, Weyl semimetals have attracted extensive interest. Taking the pyrochlore iridates A2Ir2O7（A=Y or rare earth element） as an example, we discuss the novel properties of Weyl semimetals. Their Weyl nodes are robust, they have special surface states in the form of Fermi arcs, the anomalous Hall effect is proportional to the separation between the Weyl nodes, and they have novel transport properties. We also discuss some materials predicted to be Weyl semimetals, and recent experimental progress.