Centers & Labs

RIKEN Center for Emergent Matter Science

Emergent Superstructure Research Unit

Unit Leader: Yuichi Yamasaki (Ph.D.)
Yuichi  Yamasaki(Ph.D.)

In strongly correlated electron system, orderings of electronic degrees of freedom, such as charge, spin and orbital, show various intriguing emergent phenomena and functionalities, such as magneto-electric multiferroics. We investigate the spatial modulation of electronic state by synchrotron x-ray- and neutron- diffraction and spectroscopic study for understanding these phenomena. We also aim to develop novel resonant x-ray diffraction measuring techniques to discover new emergent phenomena in strongly correlated electron system.

Main Research Field

Physics

Related Research Fields

Engineering / Materials Sciences

Research Subjects

  • Multiferroics and magnetoelectric effect
  • X-ray diffraction and spectroscopic studies in strongly-correlated electron systems
  • Neutron diffraction and spectroscopic studies in strongly-correlated electron systems

Selected Publications

Papers with an asterisk(*) are based on research conducted outside of RIKEN.
  1. Yamasaki, Y., Fujioka, J., Nakao, H., Okamoto, J., Sudayama, T., Murakami, Y., Nakamura, M., Kawasaki, M., Arima, T., and Tokura, Y.:
    “Surface Ordering of Orbitals at a Higher Temperature in LaCoO3 Thin Film”
    J. Phys. Soc. Jpn. 85, 023704 (2016)
  2. Yamasaki, Y., Morikawa, D., Honda, T., Nakao, H., Murakami, Y., Kanazawa, N., Kawasaki, M., Arima, T., and Tokura, Y.:
    “Dynamical Process of Skyrmion-Helical Magnetic Transformation in Chiral-Lattice Magnet FeGe as Probed by Small-Angle Resonant Soft X-ray Scattering”
    Phys. Rev. B 92, 220421(R) (2015)
  3. Yamasaki, Y., Nakao, H., Murakami, Y., Nakajima, T., Sampietro, A. L., Ohsumi, H., Takata, M., Arima, T., and Tokura, Y.:
    “X-ray induced lock-in transition of cycloidal magnetic order in a multiferroic perovskite manganite”
    Phys. Rev. B 91, 100403(R) (2015)
  4. *Yamasaki, Y. , Kohara, Y. , and Tokura, Y.:
    "Quantum Magnetoelectric effect in Iron Garnet"
    Physical Review B 80, 140412 (R) (2009).
  5. *Yamasaki, Y. , Sagayama, H. , Abe, N. , Arima, T. , Sasai, K. , Matsuura, M. , Hirota, K. , Okuyama, D. , Noda, Y. , Tokura Y.:
    "Cycloidal Spin Order in the a-axis Polarized Ferroelectric Phase of Orthorhombic Perovskite Manganite"
    Physical Review Letters 101, 097204 (2008).
  6. *Yamasaki, Y. , Sagayama, H. , Goto, T. , Matsuura, M. , Hirota, K. , Arima, T. , and Tokura Y.:
    "Electric Control of Spin Helicity in a Magnetic Ferroelectric"
    Physical Review Letters 98, 147204 (2007).
  7. *Yamasaki, Y. , Sagayama, H. , Goto, T. , Matsuura, M. , Hirota, K. , Arima, T. , and Tokura Y.:
    "Electric Control of Spin Helicity in a Magnetic Ferroelectric"
    Physical Review Letters 98, 147204 (2007).
  8. *Yamasaki, Y. , Miyasaka, S. , Kaneko, Y. , He, J.-P. , Arima, T. , and Tokura Y.:
    "Magnetic Reversal of the Ferroelectric Polarization in a Multiferroic Spinel Oxide"
    Physical Review Letters 96, 207204 (2006).