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 2012/08
形態種別 研究論文
標題 Manifestation of Topological Protection in Transport Properties of Epitaxial Bi2Se3 Thin Films
執筆形態 その他
掲載誌名 PHYSICAL REVIEW LETTERS
出版社・発行元 AMER PHYSICAL SOC
巻・号・頁 109(6)
著者・共著者 A. A. Taskin,Satoshi Sasaki,Kouji Segawa,Yoichi Ando
概要 The massless Dirac fermions residing on the surface of three-dimensional topological insulators are protected from backscattering and cannot be localized by disorder, but such protection can be lifted in ultrathin films when the three-dimensionality is lost. By measuring the Shubnikov-de Haas oscillations in a series of high-quality Bi2Se3 thin films, we revealed a systematic evolution of the surface conductance as a function of thickness and found a striking manifestation of the topological protection: The metallic surface transport abruptly diminishes below the critical thickness of similar to 6 nm, at which an energy gap opens in the surface state and the Dirac fermions become massive. At the same time, the weak antilocalization behavior is found to weaken in the gapped phase due to the loss of pi Berry phase.
DOI 10.1103/PhysRevLett.109.066803
ISSN 0031-9007
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