ARPES study of the epitaxially grown topological crystalline insulator SnTe(111)

Abstract

SnTe is a prototypical topological crystalline insulator, in which the gapless surface state is protected by a crystal symmetry. The hallmark of the topological properties in SnTe is the Dirac cones projected to the surfaces with mirror symmetry, stemming from the band inversion near the L points of its bulk Brillouin zone, which can be measured by angle-resolved photoemission. We have obtained the (111) surface of SnTe film by molecular beam epitaxy on BaF2(111) substrate. Photon-energy-dependence of in situ angle-resolved photoemission, covering multiple Brillouin zones in the direction perpendicular to the (111) surface, demonstrate the projected Dirac cones at the (Gamma) over bar and (M) over bar points of the surface Brillouin zone. In addition, we observe a Dirac-cone-like band structure at the Gamma point of the bulk Brillouin zone, whose Dirac energy is largely different from those at the I, and Pi points. (C) 2016 Elsevier B.V. All rights reserved.