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arXiv · 1611.03151

Interfacial-state coupling induced topological phase transitions in SnTe (110) thin film

Xiao Li·Qian Niu
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Abstract

A defining feature of topological insulating phases is symmetry-protected interfacial Dirac states. SnTe is a representative topological crystalline insulator, of which (110) thin films have two symmetry-unrelated valleys of interfacial states. With the help of valley-contrasting couplings of interfacial states, we design various two-dimensional topological phases in (110) SnTe thin film systems. Our first-principles calculations demonstrate that surface-state coupling strengths of two valleys independently vary with the thickness of the thin film, leading to both two-dimensional topological crystalline insulator and quantum spin Hall insulator. Most interestingly, by constructing a nanoribbon array of SnTe thin film, edge-state couplings of nanoribbons can further induce topological phase transition between the above topological phases with high tunability, which offers multi-mode quantum transport with potential use in electronic and spintronic devices.

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Xiao Li, Qian Niu. 2016-11-10. Interfacial-state coupling induced topological phase transitions in SnTe (110) thin film. https://doi.org/10.1103/physrevb.95.241411

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