We have performed angle-resolved photoemission spectroscopy (ARPES) on the (111) surface of the topological crystalline insulator SnTe. Distinct from a pair of Dirac-cone surface states across the X̄ point of the surface Brillouin zone on the (001) surface, we revealed two types of Dirac-cone surface states each centered at the Γ̄ and M̄ points, which originate from the bulk-band inversion at the L points. We also found that the energy location of the Dirac point and the Dirac velocity are different from each other. This ARPES experiment demonstrates the surface states on different crystal faces of a topological material, and it elucidates how mirror-symmetry-protected Dirac cones of a topological crystalline insulator show up on surfaces with different symmetries.
|Physical Review B - Condensed Matter and Materials Physics
|Published - 2013 Dec 26