Direct visualization of current-induced spin accumulation in topological insulators.

ABSTRACT: Charge-to-spin conversion in various materials is the key for the fundamental understanding of spin-orbitronics and efficient magnetization manipulation. Here we report the direct spatial imaging of current-induced spin accumulation at the channel edges of Bi₂Se₃ and BiSbTeSe₂ topological insulators as well as Pt by a scanning photovoltage microscope at room temperature. The spin polarization is along the out-of-plane direction with opposite signs for the two channel edges. The accumulated spin direction reverses sign upon changing the current direction and the detected spin signal shows a linear dependence on the magnitude of currents, indicating that our observed phenomena are current-induced effects. The spin Hall angle of Bi₂Se₃, BiSbTeSe₂, and Pt is determined to be 0.0085, 0.0616, and 0.0085, respectively. Our results open up the possibility of optically detecting the current-induced spin accumulations, and thus point towards a better understanding of the interaction between spins and circularly polarized light.

SUBMITTER: Liu Y 

PROVIDER: S-EPMC6021425 | biostudies-literature | 2018 Jun

REPOSITORIES: biostudies-literature