Realization of Helical-Spintronics

Researcher name

PI<br> Graduate School of Engineering<br> Prof. Makoto Kohda image

PI
Graduate School of Engineering
Prof. Makoto Kohda

Co-PI<br> RIEC<br> Assoc Prof. Shun Kanai image

Project Summary

By focusing on spatial structure on electron spins as well as local magnetic moments in nano scale, we will investigate the fundamental technologies for next-generation non-volatile memories and quantum information processing, based on the dynamics of spatial spin/magnetic structures. By understanding the physics of spatial spin/magnetic structures both in semiconductors and ferromagnetic metals, we will establish new field so called “Helical-Spintronics”.

We will tackle this new field of Helical-Spintronics with two young scientist (Kohda/Kanai) and two collaborators in overseas who are in the front runners in the field of Spintronics and Quantum information technology.

Results

【2022】

【2021】

【2020】

【2019】

１．Spin transfer torque from heavy metal to molecular magnet　(H. Gamou et al., Nano Letters 20, 75-80 (2020).)

Platinum holds strong spin-orbit interaction (SOI). Recent study also shows additional SOI at the surface and interface due to the breaking of structure inversion symmetry. (J-C. Ryu et al. Phys. Rev. Lett. 116, 256802 (2016)).

Here, we demonstrated the strong reduction of phase coherence in Fe(II)-phthalocyanine (FePC) / platinum (Pt) interface (Fig.1) and showed the possibility for spin transfer between FePc and Pt. Figures 2(a) and 2(b) show magneto-conductance with different temperatures for FePt / Pt and metal-free phthalocyanine (H₂PC) / Pt structures, respectively. In H₂PC/Pt, weak antilocalization was observed in low temperature, indicating the spin relaxation in Pt. However, FePt/Pt did not show any quantum interference effect. This implies the enhancement of phase decoherence by the molecular magnets. By the detailed magnetoresistance measurement, we pointed out the possibility for spin transfer from Pt to FePc.