Topological Surface Transport in Epitaxial SnTe Thin Films Grown on Bi2Te3

TL;DR

This study demonstrates the growth of epitaxial SnTe thin films on Bi2Te3 and provides transport evidence of topological surface states, revealing coexistence of p- and n-type carriers and Dirac fermions on the surface.

Contribution

First demonstration of epitaxial SnTe on Bi2Te3 with transport evidence of topological surface states and coexistence of carriers.

Findings

Coexistence of p- and n-type carriers in 30-nm SnTe films

Transport evidence of Dirac fermions on SnTe surface

Intrinsic downward band bending enabling surface state observation

Abstract

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.