Emergent Photodynamics Research Team

Principal Investigator

PI Name Naoki Ogawa
Degree D.Eng.
Title Team Leader
Brief Resume
2004D.Eng., University of Tokyo
2004Postdoctoral Associate, University of California at Irvine
2004Research Fellow of the Japan Society for the Promotion of Science
2006Project Assistant Professor, University of Tokyo
2008Assistant Professor, University of Tokyo
2012ASI Research Scientist, RIKEN
2013Senior Research Scientist, RIKEN Center for Emergent Matter Science
2015Unit Leader, Emergent Photodynamics Research Unit, RIKEN Center for Emergent Matter Science
2017JST PRESTO Researcher (-present)
2018Team Leader, Emergent Photodynamics Research Team, RIKEN Center for Emergent Matter Science (-present)


Our research team explores novel photodynamics of electron/spin/lattice in bulk crystals and at thin-film interfaces emerging via electron-correlation and strong spin-orbit interactions. Examples are the spin current generation mediated by photoexcited Dirac/Weyl electrons and the ultrafast coherent control/spectroscopy of topological electrons/spin-textures. With a strong command of photons, we try to realize new photomagnetic effects in solids, and visualize the spatiotemporal propagation of various elementally excitations at the sub-diffraction limit.

Research Fields

Physics, Engineering, Materials Sciences


Strongly correlated electron system
Spin-orbit interaction
Ultrafast spectroscopy


Photoinduced dynamics in topological spin textures

High-speed magnetic memories and photonic-magnonic interconnections will be realized by using the pulsed-optical-control of spins. For this purpose, the inverse-Faraday effect, one of the optomagnetic phenomena, is promising, where circularly-polarized laser pulses at non-absorbing photon energy can induce effective magnetic fields via strong spin-orbit interactions. We demonstrated that the collective dynamics of magnetic skyrmions, topologically-protected nano-scale spin vortices, can be characterized by using the inverse-Faraday excitation and time-resolved magneto-optics with sub-picosecond time-resolution. We also found that magnetoelastic waves, coupled propagation of magnon and phonon, can be excited in iron garnet films by photoexcitation. The time-resolved microscopy on the magnetoelastic wave revealed that this traveling spin excitation shows an attractive interaction with magnetic bubbles (skyrmions) and domain walls, whose efficiency strongly depends on the curvature of the local spin texture.

(a) Schematics for the impulsive Raman excitation.
(b) Rotation dynamics of magnetic skyrmions in Cu2OSeO3.
(c) Magneto-optical microscopy on photoexcited magnetoelastic waves.
(d) Optical manipulation of a magnetic bubble domain.


Naoki Ogawa

Team Leader naoki.ogawa[at]riken.jp R

Masato Sotome

Research Scientist

Shingo Toyoda

Special Postdoctoral Researcher

Ziqian Wang

Postdoctoral Researcher



2-1 Hirosawa, Wako, Saitama 351-0198 Japan