Centers & Labs

RIKEN Center for Emergent Matter Science

Electronic States Microscopy Research Team

Team Leader: Xiuzhen Yu (Ph.D.)

Magnetic skyrmion, nanometric topological spin texture arising from strong spin-orbit interaction is attracting much attention since it is considered to bear potential for future functional devices. The emergent field induced by the topological spin texture of skyrmion should deflect conducting electrons and hence cause novel magnetic transport phenomena such as the topological Hall effect. As a counteraction, the skyrmion Hall motion appears when the spin-polarized current traverses the skyrmion owing to the spin transfer torque. By utilizing advanced microscopy techniques, we have visualized the topological spin texture of a skyrmion and a skyrmion crystal in strongly correlated systems. We have successfully demonstrated an extremely small current (several orders of magnitudes lower than that for a drive of the domain wall in ferromagnets)-driven single skyrmion motion and a current-excited topological phase transition at the room temperatures.

Main Research Field

Mathematical and physical sciences

Related Research Fields

Complex systems / Engineering


  • Magnetic skyrmion
  • Microscopy
  • Atomic-level characterization of electronic states
  • Microfabrication
  • Spintronics

Selected Publications

  1. Yu, X.Z., Morikawa, D., Tokunaga, Y., Kubota, M., Kurumaji, T., Oike, H., Nakamura, M., Kagawa, F., Taguchi, Y., Arima, T., Kawasaki, M., Tokura, Y.:
    "Current-induced nucleation and annihilation of magnetic skyrmions at room temperature in a chiral magnet"
    Adv. Mater., 29, 1606178 (2017).
  2. Yu, X.Z., Tokunaga, Y., Taguchi, Y., Tokura, Y.:
    "Variation of Topology in Magnetic Bubbles in a Colossal Magnetoresistive Manganite"
    Adv. Mater., 29, 1603958 (2017).
  3. Tokunaga, Y., Yu, X.Z., White, J. S., Rønnow, H. M., Morikawa, D., Taguchi, Y., Tokura, Y.:
    "A new class of chiral materials hosting magnetic skyrmions beyond room temperature"
    Nature Commun. 6, 7638 (2015).
  4. Yu, X.Z., Tokunaga, Y., Kaneko, Y., Zhang, W.Z., Kimoto, K., Matsui, Y., Taguchi, Y., Tokura, Y.:
    "Biskyrmion states and their current-driven motion in a layered manganite"
    Nature Commun, 5:3198 (2014).
  5. Mochizuki, M., Yu, X. Z., Seki, S., Kanazawa, N., Koshibae, W., Zang, J., Mostovoy, M., Tokura, Y., Nagaosa, N.:
    "Thermally Driven Ratchet Motion of Skyrmion Microcrystal and Topological Magnon Hall Effect"
    Nature Materials, 13, 241 (2014).
  6. Park, H. S., Yu, X.Z., Aizawa, S., Tanigaki, T., Akashi, T., Takahashi, Y., Matsuda, T., Kanazawa, N., Onose, Y., Shindo, D., Tonomura, A., Tokura. Y.:
    "Observation of the magnetic flux and three-dimensional structure of skyrmion lattices by electron holography"
    Nature Nanotech, 9, 337 (2014).
  7. Yu, X. Z., Kanazawa, N., Zhang, W. Z., Nagai, T., Hara, T., Kimoto, K., Matsui, Y., Onose, Y., Tokura, Y.:
    "Skyrmion flow near room temperature in an ultra-low current density"
    Nature Commun, 3:988 (2012).
  8. Yu, X. Z., Kanazawa, N., Onose, Y., Kimoto, K., Zhang, W. Z., Ishiwata, S., Matsui, Y., Tokura, Y.:
    "Near room-temperature formation of a skyrmion crystal in thin-films of the helimagnet FeGe"
    Nature Materials, 10, 106 (2011).
  9. Yu, X. Z., Onose, Y., Kanazawa, N., Park, J. H., Han, J. H., Matsui, Y., Nagaosa, N., Tokura, Y.:
    "Real-space observation of two-dimensional skyrmion crystal"
    Nature, 465, 901 (2010).
  10. Yu, X. Z., Mathieu, R., Arima, T., Kaneko, Y., He, J. P., Uchida, M., Asaka, T., Nagai, T., Kimoto, K., Matsui, Y., Tokura, Y.:
    "Variation of charge/orbital ordering in layered manganites Pr1-xCa1+xMnO4 as investigated by transmission-electron-microscopy"
    Phys. Rev. B, 75, 174441 (2007).

Contact information

2-1 Hirosawa
Wako, Saitama
351-0198 Japan

Email: yu_x [at]