2014/10/20 by Yuichiro Ando, Takahiro Hamasaki, Takayuki Kurokawa +7 · 5 citations
Materials Science · Physics and Astronomy · #Chemical and Physical Properties of Materials #Electrode #Ferromagnetism #Graphene research and applications #Insulator (electricity) #Magnetoresistance #Polarization (electrochemistry) #Spin polarization #Surface states #Topological Materials and Phenomena #Topological insulator #cond-mat.mes-hall #cond-mat.mtrl-sci
paper · pdf · doi:10.1021/nl502546c
published as Nano Letters 14, 6226 (2014) · 13pages, 4 figures
openalex publication_date 2014/10/20 · arxiv created 2014/12/10 · arxiv updated 2014/12/11 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
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.