Abstract
We present first-principles calculations of the nontrivial surface states and their spin textures in the topological crystalline insulator SnTe. The surface state dispersion on the [001] surface exhibits four Dirac cones centered along the intersection of the mirror plane and the surface plane. We propose a simple model of two interacting coaxial Dirac cones to describe both the surface state dispersion and the associated spin texture. The out-of-plane spin polarization is found to be zero due to the crystalline and time-reversal symmetries. The in-plane spin texture shows helicity with some distortion due to the interaction of the two coaxial Dirac cones, indicating a nontrivial mirror Chern number of , distinct from the value of in a topological insulator such as Bi/Sb alloys or BiSe. The surface state dispersion and its spin texture would provide an experimentally accessible signature for determining the nontrivial mirror Chern number.
- Received 30 April 2013
DOI:https://doi.org/10.1103/PhysRevB.87.235317
©2013 American Physical Society