セガワ コウジ   SEGAWA KOJI
  瀬川 耕司
   所属   京都産業大学  理学部 物理科学科
   職種   教授
言語種別 英語
発行・発表の年月 2012/01
形態種別 研究論文
標題 Tunable Dirac cone in the topological insulator Bi2-xSbxTe3-ySey
執筆形態 その他
掲載誌名 NATURE COMMUNICATIONS
出版社・発行元 NATURE PUBLISHING GROUP
巻・号・頁 3
著者・共著者 T. Arakane,T. Sato,S. Souma,K. Kosaka,K. Nakayama,M. Komatsu,T. Takahashi,Zhi Ren,Kouji Segawa,Yoichi Ando
概要 The three-dimensional topological insulator is a quantum state of matter characterized by an insulating bulk state and gapless Dirac cone surface states. Device applications of topological insulators require a highly insulating bulk and tunable Dirac carriers, which has so far been difficult to achieve. Here we demonstrate that Bi2-xSbxTe3-ySey is a system that simultaneously satisfies both of these requirements. For a series of compositions presenting bulk-insulating transport behaviour, angle-resolved photoemission spectroscopy reveals that the chemical potential is always located in the bulk band gap, whereas the Dirac cone dispersion changes systematically so that the Dirac point moves up in energy with increasing x, leading to a sign change of the Dirac carriers at x similar to 0.9. Such a tunable Dirac cone opens a promising pathway to the development of novel devices based on topological insulators.
DOI 10.1038/ncomms1639
ISSN 2041-1723
PermalinkURL https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84863011037&origin=inward