Abstract
Intensive effort has recently been made in search of topological insulators (TIs) that have great potential in spintronics applications. In this paper, a novel concept of overlayer induced interfacial TI phase in conventional semiconductor surface is proposed. The first-principles calculations demonstrate that a -band-element , Bi, and Pb) decorated -band surface, such as Au/Si(111) surface /Au/Si(111)] of an existing experimental system, offers a promising prototype for TIs. Specifically, Bi/Au/Si(111) and Pb/Au/Si(111) are identified to be large-gap TIs. A band inversion mechanism induced by growth of in the Au/Si(111) surface is revealed to function at different coverage of with different lattice symmetries, suggesting a general approach of interface orbital engineering of large-gap TIs via tuning the interfacial atomic orbital position of relative to Au.
- Received 1 November 2015
- Revised 28 January 2016
DOI:https://doi.org/10.1103/PhysRevB.93.115117
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