Centers & Labs

RIKEN Center for Emergent Matter Science

Dynamic Emergent Phenomena Research Unit

Unit Leader: Fumitaka Kagawa (Ph.D.)
Fumitaka  Kagawa(Ph.D.)

Our research unit explores dynamic phenomena exhibited by strongly correlated electron systems in both bulk specimen and device structures to construct a new principle in condensed matter science. In particular, we study external-field-driven dynamic phenomena exhibited by sub-micron-scale structures, such as topological spin textures and domain walls, using spectroscopy of dielectric responses and resistance fluctuations from the millihertz to gigahertz region. We also pursue real-space observations and measurements of local physical properties using scanning probe microscopy as a complementary approach. We are aiming to control novel physical properties exhibited by topological structures in condensed matter systems on the basis of knowledge obtained from these methods.

Main Research Field

Mathematical and physical sciences

Related Research Fields

Interdisciplinary science and engineering / Engineering

Keywords

  • Metal-insulator transition
  • Phase-change memory
  • Scanning probe microscopy
  • Magnetic skyrmion

Selected Publications

  1. Kagawa, F. and Oike. H.:
    "Quenching of Charge and Spin Degrees of Freedom in Condensed Matter"
    Adv. Mater., doi: 10.1002/adma.201601979 (2016).
  2. Kagawa, F., Minami, N., Horiuchi, and Tokura, Y.:
    "Athermal domain-wall creep near a ferroelectric quantum critical point"
    Nature Commun. 7:10675 doi: 10.1038/ncomms10675 (2016).
  3. Oike, H., Kikkawa, A., Kanazawa, N., Taguchi, Y., Kawasaki, M., Tokura, Y., and Kagawa, F.:
    "Interplay between topological and thermodynamic stability in a metastable magnetic skyrmion lattice"
    Nature Phys. 12, 62-66 (2016).
  4. Oike, H., Kagawa, F., Ogawa, N., Ueda, A., Mori, H., Kawasaki, M., and Tokura, Y.:
    "Phase-change memory function of correlated electrons in organic conductors"
    Phys. Rev. B 91, 041101(R) (2015).
  5. Kagawa, F., Sato, T., Miyagawa, K., Kanoda, K., Tokura, Y., Kobayashi, K., Kumai, R., and Murakami, Y.:
    "Polarization Switching Ability Dependent on Multidomain Topology in a Uniaxial Organic Ferroelectric"
    Nano Lett. 14, 239-243 (2014).
  6. Sato, T., Kagawa, F., Kobayashi, K., Miyagawa, K., Kanoda, K., Kumai, R., Murakami, Y., and Tokura, Y.:
    "Emergence of nonequilibrium charge dynamics in a charge-cluster glass"
    Phys. Rev. B 89, 121102 (2014).
  7. Kagawa, F., Sato, T., Miyagawa, K., Kanoda, K., Tokura, Y., Kobayashi, K., Kumai, R., and Murakami, Y.:
    "Charge-cluster glass in an organic conductor"
    Nature Phys. 9, 419-422 (2013).
  8. Horiuchi, S., Kagawa, F., Hatahara, K., Kobayashi, K., Kumai, R., Murakami, Y., and Tokura, Y.:
    "Above room-temperature ferroelectricity and antiferroelectricity in benzimidazoles"
    Nature Commun. 3:1308 doi: 10.1038/ncomms2322 (2012).
  9. Kagawa, F., Horiuchi, S., Tokunaga, M., Fujioka, J., and Tokura, Y.:
    "Ferroelectricity in one-dimensional organic quantum magnet"
    Nature Phys. 6, 169-172 (2010).
  10. Kagawa, F., Mochizuki, M., Onose, Y., Murakawa, H., Kaneko, Y., Furukawa N., and Tokura, Y.:
    "Dynamics of Multiferroic Domain Wall in Spin-Cycloidal Ferroelectric DyMnO3"
    Phys. Rev. Lett. 102, 057604 (2009).

Lab Members

Principal Investigator

Fumitaka Kagawa
Unit Leader

Core Members

Hiroshi Oike
Postdoctoral Researcher
Takuro Sato
Postdoctoral Researcher

Contact information

209 Frontier Research Laboratory
2-1 Hirosawa,
Wako, Saitama
351-0198, Japan

Email: fumitaka.kagawa [at] riken.jp

Related links

Recent research results

October 21, 2016: RIKEN RESEARCH
‘Snap freezing’ produces different state