摘要
In last decades, topological materials [1-3] have attracted lots of research interest. Topological Kondo insulator (TKI) [4], as an exotic quantum state, has been proposed theoretically in two hexaborides StuB6 and YbB6, in which there is a d/f(p) band inversion at momentum point X [5]. There are lots of experimental work supporting the TKI state and metallic sur- face state in typical Kondo insulator SmB6 [6-10]. However, more and more experimental results demonstrated that YbB6 is trivial insulator at ambient pressure [11]. Under high pres- sure, the band gap of YbB6 will close and the dip band inver- sion can happen under pressure about 15 GPa [12].
In last decades,topological materials[1-3]have attracted lots of research interest.Topological Kondo insulator(TKI)[4],as an exotic quantum state,has been proposed theoretically in two hexaborides Sm B6and Yb B6,in which there is a d/f(p)band inversion at momentum point X[5].There are lots of experimental work supporting the TKI state and metallic surface state in typical Kondo insulator Sm B6[6-10].However,more and more experimental results demonstrated that Yb B6is trivial insulator at ambient pressure[11].Under high pressure,the band gap of Yb B6will close and the d/p band inversion can happen under pressure about 15 GPa[12].
基金
supported by the National Natural Science Foundation of China(Grant Nos.11604068,and 51371010)
the Fundamental Research Funds for the Central Universities