Gibson Q D, Evtushinsky D, Yaresko A N, Zabolotnyy V B, Ali Mazhar N, Fuccillo M K, Van den Brink J, Büchner B, Cava R J, Borisenko S V
Department of Chemistry, Princeton University, Princeton, New Jersey, 08544, USA.
Leibniz Institute for Solid State and Materials Research, IFW Dresden, D-01069 Dresden, Germany.
Sci Rep. 2014 Jun 4;4:5168. doi: 10.1038/srep05168.
We present an ARPES study of the surface states of Ru2Sn3, a new type of a strong 3D topological insulator (TI). In contrast to currently known 3D TIs, which display two-dimensional Dirac cones with linear isotropic dispersions crossing through one point in the surface Brillouin Zone (SBZ), the surface states on Ru2Sn3 are highly anisotropic, displaying an almost flat dispersion along certain high-symmetry directions. This results in quasi-one dimensional (1D) Dirac electronic states throughout the SBZ that we argue are inherited from features in the bulk electronic structure of Ru2Sn3 where the bulk conduction bands are highly anisotropic. Unlike previous experimentally characterized TIs, the topological surface states of Ru2Sn3 are the result of a d-p band inversion rather than an s-p band inversion. The observed surface states are the topological equivalent to a single 2D Dirac cone at the surface Brillouin zone.
我们展示了对新型强三维拓扑绝缘体（TI）Ru2Sn3表面态的角分辨光电子能谱（ARPES）研究。与目前已知的三维TI不同，后者在表面布里渊区（SBZ）中呈现出二维狄拉克锥，其线性各向同性色散在一点相交，而Ru2Sn3上的表面态具有高度各向异性，在某些高对称方向上呈现出几乎平坦的色散。这导致在整个SBZ中出现准一维（1D）狄拉克电子态，我们认为这是从Ru2Sn3的体电子结构特征继承而来的，其中体导带具有高度各向异性。与之前实验表征的TI不同，Ru2Sn3的拓扑表面态是d-p带反转的结果，而不是s-p带反转。观察到的表面态在拓扑上等同于表面布里渊区的单个二维狄拉克锥。
