Negative spin-to-charge current induced by interfacial spin-orbit coupling in Pt/monolayer 1T-TiSe/graphene/yttrium iron garnet quadruple heterostructures

Pt/単層1T-TiSe/グラフェン/イットリウム鉄ガーネットからなる四重層ヘテロ構造における界面スピン軌道相互作用によって引き起こされる負のスピン-電荷変換電流

Choi, J. W.*; 吉川 貴史; Lee, S.-K.*; 他13名*

Choi, J. W.*; Kikkawa, Takashi; Lee, S.-K.*; 13 of others*

Strong spin-orbit coupling (SOC) materials and graphene have recently emerged as promising interfacial layers for tailoring spin transport in normal metal/ferromagnet heterostructures. However, spin-to-charge conversion in Pt/two-dimensional (2D) layer/graphene/yttrium iron garnet (YIG) heterostructures remains experimentally unexplored. This study investigates the effects of monolayer graphene and its interfacial coupling with a non-magnetic 2D transition metal dichalcogenide (TMDC) with relatively strong SOC on the longitudinal spin Seebeck effect (LSSE) in Pt/TiSe (or ZrSe)/graphene/YIG quadruple heterostructures. Interfacial SOC between TMDC and graphene is demonstrated to induce an additional spin-to-charge conversion channel in the Pt layer, generating a charge current opposite in direction to the conventional inverse spin Hall effect-induced current from YIG and thereby leading to a net suppression of the LSSE signal. Thus, the study highlights the potential of non-magnetic TMDC interlayers for modulating spin transport, offering new design pathways for spintronic devices.