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Topological quantum phase transitions driven by external electric fields in Sb?Te? thin films.

ABSTRACT: Using first-principles calculations, we show that topological quantum phase transitions are driven by external electric fields in thin films of Sb(2)Te(3). The film, as the applied electric field normal to its surface increases, is transformed from a normal insulator to a topological insulator or vice versa depending on the film thickness. We identify the band topology by directly calculating the Z(2) invariant from electronic wave functions. The dispersion of edge states is also found to be consistent with the bulk band topology in view of the bulk-boundary correspondence. We present possible applications of the topological phase transition as an on/off switch of the topologically protected edge states in nano-scale devices.

SUBMITTER: Kim M

PROVIDER: S-EPMC3271865 | biostudies-literature | 2012 Jan

REPOSITORIES: biostudies-literature

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Topological quantum phase transitions driven by external electric fields in Sb₂Te₃ thin films.

Kim Minsung M Kim Choong H CH Kim Heung-Sik HS Ihm Jisoon J

Proceedings of the National Academy of Sciences of the United States of America 20111227 3

Using first-principles calculations, we show that topological quantum phase transitions are driven by external electric fields in thin films of Sb(2)Te(3). The film, as the applied electric field normal to its surface increases, is transformed from a normal insulator to a topological insulator or vice versa depending on the film thickness. We identify the band topology by directly calculating the Z(2) invariant from electronic wave functions. The dispersion of edge states is also found to be con ...[more]

PMID: 22203972

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