Emergent Spintronics Research Unit

Principal Investigator

PI Name Yoshinori Tokura
Degree D.Eng.
Title Unit Leader


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.

Research Fields

Physics, Engineering, Chemistry, Materials Sciences


Strongly correlated electron system


Observation of skyrmions in a multiferroic material

Magnetic skyrmion is a topologically stable particle-like object, which appears as nanometer-scale vortex-like spin texture in a chiral-lattice magnet. In metallic materials, electrons moving through skyrmion spin texture gain a nontrivial quantum Berry phase, which provides topological force to the underlying spin texture and enables the current-induced manipulation of magnetic skyrmion. Such electric controllability, in addition to the particle-like nature, is a promising advantage for potential spintronic device applications. Recently, we newly discovered that skyrmions appear also in an insulating chiral-lattice magnet Cu2OSeO3. We find that the skyrmions in insulator can magnetically induce electric polarization through the relativistic spin-orbit interaction, which implies possible manipulation of the skyrmion by external electric field without loss of joule heating. The present finding of multiferroic skyrmion may pave a new route toward the engineering of novel magnetoelectric devices with high energy efficiency.

Crystal structure of chiral-lattice insulator Cu2OSeO3, and magnetic skyrmion inducing electric polarization.


Yoshinori Tokura

Unit Leader tokura[at]riken.jp R

Rina Takagi

Research Scientist

Khanh Nguyen

Postdoctoral Researcher


  • Nov 18, 2016 RIKEN RESEARCH Switched-on skyrmions
    A lattice of magnetic vortices can be created or destroyed simply by applying an electric field
  • Oct 17, 2014 RIKEN RESEARCH Light finds a one-way street
    A multiferroic material displays a novel spin structure that allows light to travel in only one direction
  • Mar 20, 2014 RIKEN RESEARCH Dance of the skyrmions
    Skymions are ‘whirls’ in the magnetization of certain magnetic materials that show promise for future electronics and spintronics applications if they can be harnessed and manipulated.