RIKEN Center for Emergent Matter Science Emergent Quantum Spintronics Research Unit

Unit Leader: Tomoyuki Yokouchi (D.Eng.)

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Research Summary

The aim of this unit is to understand the quantum and emergent properties in spintronics, which aims to utilize both the charge and spin of electrons, and to construct a new scheme for them. In particular, by employing microfabrication techniques, we will develop novel spintronic and quantum transport phenomena in various magnetic materials. Our goal is to elucidate the mechanisms driving their emergence. Furthermore, by focusing on the classical and quantum dynamics of topological spin structures, we will also work to establish a new scheme for emergent computational techniques, such as physical reservoir computing.

Main Research Fields

Mathematical & Physical Sciences

Related Research Fields

Engineering
Interdisciplinary Science & Engineering
Condensed matter physics
Applied condensed matter physics

Keywords

Spintronics
Artificial intelligence
Magnetic skyrmion
Spin dynamics
Spin Hall effect

Selected Publications

Papers with an asterisk(*) are based on research conducted outside of RIKEN.

1. *Yokouchi, T., Ikeda, Y., Morimoto, T., Shiomi, Y.:
"Giant Magnetochiral Anisotropy in Weyl Semimetal WTe₂ Induced by Diverging Berry Curvature"
Physical Review Letters 130 136301 (2023).
2. Yokouchi, T., Sugimoto, S., Rana, B., Seki, S., Ogawa, N., Shiomi, Y., Kasai, S., Otani Y.:
"Pattern recognition with neuromorphic computing using magnetic field–induced dynamics of skyrmions"
Science Advances 8 eabq5652 (2022).
3. Kitaori, A., Kanazawa, N., Yokouchi, T., Kagawa, F., Nagaosa, N., and Tokura, Y.:
"Emergent electromagnetic induction beyond room temperature"
PNAS 118, e2105422118 (2021).
4. Takagi, R., Yamasaki, Y., Yokouchi, T., Ukleev, V., Yokoyama, Y., Nakao, H., Arima, T., Tokura, Y., and Seki, S.:
"Particle-size dependent structural transformation of skyrmion lattice"
Nature Communications 11, 5685 (2020).
5. Yokouchi, T., Kagawa, K., Hirschberger, M., Otani, Y., Nagaosa, N., and Tokura, Y.:
"Emergent electromagnetic induction in a helical-spin magnet"
Nature 586, 232 (2020).
6. Yokouchi, T., Sugimoto, S., Rana, B., Seki, S., Ogawa, N., Kasai, S., and Otani, Y.:
"Creation of magnetic skyrmions by surface acoustic waves"
Nature Nanotechnology 15, 361 (2020).
7. Yokouchi, T., Hoshino, S., Kanazawa, N., Kikkawa, A., Morikawa, D., Shibata, K., Arima, T., Taguchi, Y., Kagawa, F., Nagaosa, N., Tokura, Y.:
"Current-induced dynamics of skyrmion strings"
Science Advances 4, eaat1115 (2018).
8. Yu, X., Morikawa, D., Yokouchi, T., Shibata, K., Kanazawa, N., Kagawa, F., Arima, T., Tokura, Y.:
"Aggregation and collapse dynamics of skyrmions in a non-equilibrium state"
Nature Physics 14, 832 (2018).
9. Yokouchi, T., Kanazawa, N., Kikkawa, A., Morikawa, D., Shibata, K., Arima, T., Taguchi, Y., Kagawa, F., and Tokura, Y.:
"Electrical magnetochiral effect induced by chiral spin fluctuations"
Nature Communications 8, 866 (2017).
10. Yokouchi, T., Kanazawa, N., Tsukazaki, A., Kozuka, Y., Kawasaki, M., Ichikawa, M., Kagawa, F., and Tokura, Y.:
"Stability of two-dimensional skyrmions in thin films of Mn_1-xFe_xSi investigated by the topological Hall effect"
Physical Review B 89, 064416 (2014).

Lab Members

Principal investigator

Tomoyuki Yokouchi: Unit Leader

Contact Information

Frontier Research Laboratory
2-1 Hirosawa, Wako, Saitama 351-0198, Japan
Email: tomoyuki.yokouchi [at] riken.jp