Dynamical spin-to-charge conversion on the edge of quantum spin Hall insulator

量子スピンホール絶縁体エッジにおける動的なスピン-電荷変換

荒木 康史   ; 三澤 貴宏*; 野村 健太郎*

Araki, Yasufumi; Misawa, Takahiro*; Nomura, Kentaro*

We theoretically manifest that the edge of a quantum spin Hall insulator (QSHI), attached to an insulating ferromagnet (FM), can realize a highly efficient spin-to-charge conversion. Based on a one-dimensional QSHI-FM junction, the electron dynamics on the QSHI edge is analyzed, driven by a magnetization dynamics in the FM. Under a large gap opening on the edge from the magnetic exchange coupling, we find that the spin injection into the QSHI edge gets suppressed while the charge current driven on the edge gets maximized, demanded by the band topology of the one-dimensional helical edge states.