title: Realization of tunable Dirac cone and insulating bulk states in topological insulators (Bi(1-x)Sb(x))(2)Te(3).
abstract: The bulk-insulating topological insulators with tunable surface states are necessary for applications in spintronics and quantum computation. Here we present theoretical evidence for modulating the topological surface states and achieving the insulating bulk states in solid-solution (Bi(1-x)Sb(x))(2)Te(3). Our results reveal that the band inversion occurs in (Bi(1-x)Sb(x))(2)Te(3), indicating the non-triviality across the entire composition range, and the Dirac point moves upwards till it lies within the bulk energy gap accompanying the increase of Sb concentration x. In addition, with increasing x, the formation of prominent native defects becomes much more difficult, resulting in the truly insulating bulk. The solid-solution system is a promising way of tuning the properties of topological insulators and designing novel topologically insulating devices.
authors.affiliation: School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, People's Republic of China.
authors.forename: Chengwang
authors.initials: C
authors.lastname: Niu
authors.forename: Ying
authors.initials: Y
authors.lastname: Dai
authors.forename: Yingtao
authors.initials: Y
authors.lastname: Zhu
authors.forename: Yandong
authors.initials: Y
authors.lastname: Ma
authors.forename: Lin
authors.initials: L
authors.lastname: Yu
authors.forename: Shenghao
authors.initials: S
authors.lastname: Han
authors.forename: Baibiao
authors.initials: B
authors.lastname: Huang