Emergent Spintronics Research Team

Principal Investigator

PI Name

Eiji Saitoh

Degree

Ph.D.

Title

Team Leader

Brief Resume

2001	Ph.D., Engineering, University of Tokyo
2001	Research Associate, Department of Physics, Keio University
2006	Senior Lecturer、Department of Applied Physics, Keio University.
2009	Professor, Institute for Materials Research, Tohoku University.
2012	Professor, Principal Investigator at WPI-AIMR, Tohoku University.
2018	Professor, Department of Applied Physics, University of Tokyo (-present)
2023	Team Leader, Emergent Spintronics Research Team, Quantum Information Electronics Division, RIKEN Center for Emergent Matter Science (-present)

Outline

Our research team is conducting research on various quantum spintronics phenomena in nanoscale shape-controlled composite structures of magnetic materials, inorganic and organic semiconductors, and superconductors. Focusing on quantum spin dynamics, spin transport, and the interaction between spin and macroscopic order parameters, we are conducting experiments using methods such as transport measurements, optical measurements, and ultra low temperature microwave spectroscopy. Through this research, we aim to extend spintronics to the quantum domain, construct a fundamental physics system, and apply it to information processing and energy conversion.

Research Fields

Physics, Engineering, Materials Sciences

Keywords

Spintronics
Energy conversion
Quantum device
Quantum information
Machine learning physics

Results

Creating the Principles of Future Quantum Devices with Spintronics

Quantum spintronics provides essential guiding principles for achieving innovative devices. It explores the physics of the interaction between the spin degrees of freedom of electrons and the diverse ordering in condensed matter, bridging the way to practical applications. Spin dynamics exhibiting strong nonlinearity due to the shape effects of nano magnets demonstrate exotic responses such as squeezing and nonlinear bifurcation phenomena, which can be controlled by spin and electric currents. Research on prominent nonlinear parametric processes in nano magnets is conducted, paving the way for nonlinear and quantum regimes in collective spin excitations. In particular, quantum squeezed magnons (spin waves) associated with strong nonlinearity and high coherence serve as promising magnetic quantum information carriers, offering potential applications in quantum information electronics and quantum sensors (e.g., magnetic field sensors, thermal and thermal fluctuation sensors). Furthermore, thermally squeezed magnons hold promise for applications in thermal control and power generation devices. Additionally, beyond ferromagnetic order, various ordered phases exist in condensed matter, and their coupling with electric and spin currents can yield exciting results. Leveraging the spintronics measurement techniques in our group, we also explore new realms of material science that this coupling can bring.

Parametron in nano magnets.

Members

Eiji Saitoh	Team Leader	eiji.saitoh[at]riken.jp
Takahiko Makiuchi	Research Scientist
Tomosato Hioki	Visiting Scientist
Naoto Yokoi	Visiting Scientist
Hiroki Arisawa	Visiting Scientist

Publications

T. Makiuchi, T. Hioki, H. Shimizu, K. Hoshi, M. Elyasi, K. Yamamoto, N. Yokoi, A. A. Serga, B. Hillebrands, G. E. W. Bauer, and E. Saitoh

Persistent magnetic coherence in magnets

Nat. Mater. 23, 627–632 (2024)
S. Daimon, K. Tsunekawa, S. Kawakami, T. Kikkawa, R. Ramos, K. Oyanagi, T. Ohtsuki, and E. Saitoh,

Deciphering quantum fingerprints in electric conductance

Nat. Commun. 13, 3160 (2022)
H. Arisawa, H. Shim, S. Daimon, T. Kikkawa, Y. Oikawa, S. Takahashi, T. Ono and, E. Saitoh

Observation of spin-current striction in a magnet

Nat. Commun. 13, 2440 (2022)
T. Kikkawa, D. Reitz, H. Ito, T. Makiuchi, T. Sugimoto, K. Tsunekawa, S. Daimon, K. Oyanagi, R. Ramos, S. Takahashi, Y. Shiomi, Y. Tserkovnyak, and E. Saitoh,

Observation of nuclear-spin Seebeck effect

Nat. Commun. 12, 4336 (2021)
Y. Shiomi, J. Lustikova, S. Watanabe, D. Hirobe, S. Takahashi, and E. Saitoh

Spin pumping from nuclear spin waves

Nat. Phys. 15, 22–26 (2018)
K. Uchida, S. Daimon, R. Iguchi, and E. Saitoh,

Observation of anisotropic magneto-Peltier effect in nickel

Nature 558, 95–99 (2018)