RIKEN Center for Emergent Matter Science Dynamic Emergent Phenomena Research Team

Team Leader: Fumitaka Kagawa (Ph.D.)

Japanese Page

Research Summary

Our research team 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 Fields

Mathematical & Physical Sciences

Related Research Fields

Interdisciplinary Science & Engineering
Engineering

Keywords

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

Selected Publications

1. K. Matsuura, H. Oike, V. Kocsis, T. Sato, Y. Tomioka, Y. Kaneko, M. Nakamura, Y. Taguchi, M. Kawasaki, Y. Tokura, and F. Kagawa.:
"Kinetic pathway facilitated by a phase competition to achieve a metastable electronic phase"
Phys. Rev. B 103, L041106 (2021)
2. T. Sato, A. Kikkawa, Y. Taguchi, Y. Tokura, and F. Kagawa:
"Mode locking phenomena of the current-induced skyrmion-lattice motion in microfabricated MnSi"
Phys. Rev. B 102, 180411 (2020)
3. T. Sato, W. Koshibae, A. Kikkawa, T. Yokouchi, H. Oike, Y. Taguchi, N. Nagaosa, Y. Tokura, and F. Kagawa.:
"Slow steady flow of a skyrmion lattice in a confined geometry probed by resistance narrow-band noise"
Phys. Rev. B 100, 094410 (2019)
4. H. Oike, M. Kamitani, Y. Tokura, and F. Kagawa.:
"Kinetic approach to superconductivity hidden behind a competing order"
Sci. Adv. 4, eaau3489 (2018)
5. H. Oike, M. Suda, M. Kamitani, A. Ueda, H. Mori, Y. Tokura, H. M. Yamamoto, and F. Kagawa.:
"Size effects on supercooling phenomena in strongly correlated electron systems: IrTe₂ and θ-(BEDT-TTF)₂RbZn(SCN)₄"
Phys. Rev. B 97, 085102 (2018)
6. F. Kagawa, H. Oike, W. Koshibae, A. Kikkawa, Y. Okamura, Y. Taguchi, N. Nagaosa, and Y. Tokura.:
"Current-induced viscoelastic topological unwinding of metastable skyrmion strings"
Nat. Commun. 8, 1332 (2017)
7. F. Kagawa and H. Oike.:
"Quenching of Charge and Spin Degrees of Freedom in Condensed Matter"
Adv. Mat. 29, 1601979 (2017)
8. Y. Okamura, F. Kagawa, S. Seki, and Y. Tokura.:
"Transition to and from the skyrmion lattice phase by electric fields in a magnetoelectric compound"
Nat. Commun. 7, 12669 (2016)
9. F. Kagawa, N. Minami, S. Horiuchi, and Y. Tokura.:
"Athermal domain-wall creep near a ferroelectric quantum critical point"
Nat. Commun. 7, 10675 (2016)
10. H. Oike, A. Kikkawa, N. Kanazawa, Y. Taguchi, M. Kawasaki, Y. Tokura, and F. Kagawa.:
"Interplay between topological and thermodynamic stability in a metastable magnetic skyrmion lattice"
Nat. Phys. 12, 62 (2016)