著者

Yoshimi R. Tsukazaki A. Kozuka Y. Falson J. Takahashi K. S. Checkelsky J. G. Nagaosa N. Kawasaki M. Tokura Y.

出版者

Nature Publishing Group

雑誌

Nature communications (ISSN:20411723)

巻号頁・発行日

no.6, 2015-04-14

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The three-dimensional topological insulator is a novel state of matter characterized by two-dimensional metallic Dirac states on its surface. To verify the topological nature of the surface states, Bi-based chalcogenides such as Bi2Se3, Bi2Te3, Sb2Te3 and their combined/mixed compounds have been intensively studied. Here, we report the realization of the quantum Hall effect on the surface Dirac states in (Bi1−xSbx)2Te3 films. With electrostatic gate-tuning of the Fermi level in the bulk band gap under magnetic fields, the quantum Hall states with filling factor ±1 are resolved. Furthermore, the appearance of a quantum Hall plateau at filling factor zero reflects a pseudo-spin Hall insulator state when the Fermi level is tuned in between the energy levels of the non-degenerate top and bottom surface Dirac points. The observation of the quantum Hall effect in three-dimensional topological insulator films may pave a way toward topological insulator-based electronics.UTokyo Research掲載「トポロジカル絶縁体の表面ディラック状態の量子化を実証」 URI: http://www.u-tokyo.ac.jp/ja/utokyo-research/research-news/observation-of-quantization-in-surface-dirac-states-of-topological-insulator.html