Topological surface transport in epitaxial SnTe thin films grown on Bi₂Te₃

The topological crystalline insulator SnTe has been grown epitaxially on a Bi₂Te₃ buffer layer by molecular beam epitaxy. In a 30-nm-thick SnTe film, p- and n-type carriers are found to coexist, and Shubnikov–de Haas oscillation data suggest that the n-type carriers are Dirac fermions residing on the SnTe (111) surface. This transport observation of the topological surface state in a p-type topological crystalline insulator became possible due to a downward band bending on the free SnTe surface, which appears to be of intrinsic origin.