Frontier Research Institute for Interdisciplinary Sciences
Tohoku University

Research Projects

Creative Interdisciplinary Collaboration Program 2020

Assist. Prof. Satoshi Iihama

Title Constructing natural tempo representation map and database
Priod 2021-2022

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.

Figure (a) Honeycomb lattice structure of transition-metal dichalcogenides (TMD). (b) Chirality selection rule for TMD.