Centers & Labs

RIKEN Center for Emergent Matter Science

Emergent Spintronics Research Unit

Unit Leader: Shinichiro Seki (Ph.D.)
Shinichiro  Seki(Ph.D.)

While electron is a particle with charge and spin degrees of freedom, only electronic charge is employed in the traditional semiconductor electronics. The electronics utilizing spin degree of freedom is called spintronics, and considered as a key to realize novel device with unique function and low energy consumption. By bringing the knowledge of solid state chemistry and material science to the spintronics field where only simplest ferromagnetic materials have been investigated, we newly create appropriate environment for electrons to show up various emergent spin functionality. We try to build up the new fundamental science and technology for extremely energy efficient magnetic storage/computing device, especially by combining the state-of-art concepts such as (1) nanometric spin vortex with particle nature (magnetic skyrmion), (2) electric control of magnetism, and (3) spin current as dissipationless information carrier.

Main Research Field

Engineering / Chemistry / Materials Sciences

Related Research Fields

Physics

Research Subjects

  • Crystallography and electromagnetism of magnetic skyrmion
  • Electric control of magnetism
  • Spin current physics based on material science

Selected Publications

  1. M. Mochizuki, S. Seki:
    “Magnetoelectric resonances and predicted microwave diode effect of the skyrmion crystal in a multiferroic chiral-lattice magnet”
    Phys. Rev. B 87, 134403 (2013).
  2. S. Seki, X. Z. Yu, S. Ishiwata, Y. Tokura:
    “Observation of Skyrmions in a Multiferroic Material”
    Science 336, 198 (2012).
  3. Y. Tokura, S. Seki:
    “Multiferroics with spiral spin orders”
    Adv. Mater. 22, 1554 (2010).
  4. S. Seki, N. Kida, S. Kumakura, R. Shimano, Y. Tokura:
    “Electromagnons in the spin collinear state of a triangular lattice antiferromagnet”
    Phys. Rev. Lett. 105, 097207 (2010).
  5. S. Seki, H. Murakawa, Y.Onose, Y. Tokura:
    “Magnetic digital flop of ferroelectric domain with fixed spin chirality in a triangular lattice helimagnet”
    Phys. Rev. Lett. 103, 237601 (2009).
  6. S. Seki, Y.Onose, Y. Tokura:
    “Spin-driven ferroelectricity in triangular lattice antiferromagnets ACrO2 (A = Cu, Ag, Li, or Na) “
    Phys. Rev. Lett. 101, 067204 (2008).
  7. S. Seki, Y. Yamasaki, M. Soda, M. Matsuura, K. Hirota, Y. Tokura:
    “Correlation between spin helicity and electric polarization vector in quantum-spin chain magnet LiCu2O2
    Phys. Rev. Lett. 100, 127201 (2008).

Lab Members

Principal Investigator

Shinichiro Seki
Unit Leader

Core Members

Rina Takagi
Postdoctoral Researcher
Khanh Nguyen
Postdoctoral Researcher
Masataka Kinoshita
Student Trainee