title: Electrical detection of the spin polarization due to charge flow in the surface state of the topological insulator Bi(1.5)Sb(0.5)Te(1.7)Se(1.3).
abstract: We detected the spin polarization due to charge flow in the spin nondegenerate surface state of a three-dimensional topological insulator by means of an all-electrical method. The charge current in the bulk-insulating topological insulator Bi1.5Sb0.5Te1.7Se1.3 (BSTS) was injected/extracted through a ferromagnetic electrode made of Ni80Fe20, and an unusual current-direction-dependent magnetoresistance gave evidence for the appearance of spin polarization, which leads to a spin-dependent resistance at the BSTS/Ni80Fe20 interface. In contrast, our control experiment on Bi2Se3 gave null result. These observations demonstrate the importance of the Fermi-level control for the electrical detection of the spin polarization in topological insulators.
authors.affiliation: Department of Electronic Science and Engineering, Kyoto University , Kyoto 615-8531, Japan.
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Ando
authors.forename: Takahiro
authors.initials: T
authors.lastname: Hamasaki
authors.forename: Takayuki
authors.initials: T
authors.lastname: Kurokawa
authors.forename: Kouki
authors.initials: K
authors.lastname: Ichiba
authors.forename: Fan
authors.initials: F
authors.lastname: Yang
authors.forename: Mario
authors.initials: M
authors.lastname: Novak
authors.forename: Satoshi
authors.initials: S
authors.lastname: Sasaki
authors.forename: Kouji
authors.initials: K
authors.lastname: Segawa
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Ando
authors.forename: Masashi
authors.initials: M
authors.lastname: Shiraishi
keywords: electrical spin detection; spin current; spin-momentum locking; topological insulator