Manipulation of topological states and the bulk band gap using natural heterostructures of a topological insulator

K. Nakayama, K. Eto, Y. Tanaka, T. Sato, S. Souma, T. Takahashi, Kouji Segawa, Yoichi Ando

Research output: Contribution to journalArticle

64 Citations (Scopus)

Abstract

We have performed angle-resolved photoemission spectroscopy on (PbSe) 5(Bi2Se3)3m, which forms a natural multilayer heterostructure consisting of a topological insulator and an ordinary insulator. For m=2, we observed a gapped Dirac-cone state within the bulk band gap, suggesting that the topological interface states are effectively encapsulated by block layers; furthermore, it was found that the quantum confinement effect of the band dispersions of Bi2Se3 layers enhances the effective bulk band gap to 0.5eV, the largest ever observed in topological insulators. For m=1, the Dirac-like state is completely gone, suggesting the disappearance of the band inversion in the Bi2Se 3 unit. These results demonstrate that utilization of naturally occurring heterostructures is a new promising strategy for manipulating the topological states and realizing exotic quantum phenomena.

Original languageEnglish
Article number236804
JournalPhysical Review Letters
Volume109
Issue number23
DOIs
Publication statusPublished - 2012 Dec 4

ASJC Scopus subject areas

  • Physics and Astronomy(all)

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