Frontier Research Institute for Interdisciplinary Sciences
Tohoku University

Recently, it is known that electronic structure with spin-momentum coupling (locking) can be realized by using two-dimensional (2D) materials such as graphene. In the case of single layer of transition-metal dichalcogenides (TMD) with honeycomb lattice structure [Fig. (a)] such as MoS2, specific light-spin coupling can be realized owing to its structure with inversion symmetry breaking. In this structure light with different helicity is absorbed with different K points (K and K’ valley), which is called chirality selection rule [Fig. (b)]. Circular photo-luminescence effect in 2D-MoS2 has been observed, however, magnetization manipulation in such a structure have never been reported. On the other hand, we demonstrated recently that spin in a heavy metal thin film can be induced by circularly polarized light and magnetization in an adjacent ferromagnet can be manipulated by the light-induced spin. We can expect large light-spin conversion and efficient light-driven magnetization manipulation by using 2D materials. In this FRIS collaboration, we will try to develop light-spin coupling using 2D materials for light-driven magnetization manipulation by collaborating with Dr. Nguyen of FRIS, theoretical researcher of electronic band structure in 2D materials, and Dr. Idzuchi of AIMR, specialist for making 2D materials.