RIKEN Center for Emergent Matter Science Extreme Quantum Matter Physics RIKEN ECL Research Unit

RIKEN ECL Unit Leader: Yukako Fujishiro (Ph.D.)

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Research Summary

In our unit, we aim to investigate intriguing emergent phenomena in magnetic topological materials and strongly correlated electron system, with a particular emphasis on “extreme” conditions previously unattainable in earlier experiments. For instance, we employ microfabrication techniques on single crystalline quantum materials using focused ion beams. This enables us to (i) explore responses under ultra-high pressure, (ii) generate magnetization dynamics in spin textures through high-density currents, and (iii) manipulate carrier densities through ion intercalation. Through these innovative approaches, we aim to reveal new quantum phases and elucidate their electronic functionalities.

Main Research Fields

Mathematical & Physical Sciences

Related Research Fields

Engineering
Chemistry
Interdisciplinary Science & Engineering
Magnetism, superconductivity and strongly correlated systems-related
Applied physical properties-related
Inorganic materials and properties-related

Keywords

Magnetic topological material
Strongly correlated electron system
Charge transport phenomena
Intercalation
Ultra-high pressure

Selected Publications

1. Fujishiro, Y., Terakura, C., Miyake, A., Kanazawa, N., Nakazawa, K., Ogawa, N., Kadobayashi, H., Kawaguchi, S., Kagayama, T., Tokunaga, M., Kato, Y., Motome, Y., Shimizu, K., and Tokura, Y.:
"Anomalous charge transport upon quantum melting of chiral spin order"
arXiv:2310.04823
2. Matsuoka, H., Fujishiro, Y., Minami, S., Koretsune, T., Arita, R., Tokura, Y., and Iwasa, Y.:
"Electron-doped magnetic Weyl semimetal LixCo3Sn2S2 by bulk-gating"
arXiv:2312.17547
3. Singh, D., Fujishiro, Y., Hayamai, S., Mooday, S., Nomoto, T., Baral, P. R., Ukleev, V., Cubitt, R., Steinke, N-J., Gawryluk, D. J., Pomjakushina, E., Onuki, Y., Arita, R., Tokura, Y., Kanazawa, N., and White, J. S.:
"Transition between distinct hybrid skyrmion textures through their hexagonal-to-square crystal transformation in a polar magnet"
Nature Communications 14, 8050 (2023)
4. Kanazawa, N., Fujishiro, Y., Akiba, K., Kurihara, R., Mitamura, H., Miyake, A., Matsuo, A., Kindo, K., Tokunaga, M., and Tokura, Y.:
"Topological phase transitions and critical phenomena associated with unwinding of spin crystals by high magnetic fields"
Journal of the Physical Society of Japan 91, 101002 (2022)
5. Fujishiro, Y., Kanazawa, N., Kurihara, R., Ishizuka, H., Hori, T., Yasin, F. S., Yu, X. Z., Tsukazaki, A., Ichikawa, M., Kawasaki, M., Nagaosa, N., Tokunaga, M., and Tokura, Y.:
"Giant anomalous Hall effect from spin-chirality scattering in a chiral magnet"
Nature Communications 12, 317 (2021)
6. Okamura, Y., Minami, S., Kato, Y., Fujishiro, Y., Kaneko, Y., Ikeda, Muramoto, J., Kanko, R., Ueda, K., Kocsis, V., Kanazawa, N., Taguchi, Y., Koretsune, T., Fujiwara, K., Tsukazaki, A., Arita, R., Tokura, Y., and Tokahashi, Y.:
"Giant magneto-optical responses in magnetic Weyl semimetal Co3Sn2S2"
Nature Communications 11, 4619 (2020)
7. Tanaka, M., Fujishiro, Y., Mogi, M., Kaneko, Y., Yokosawa, T., Kanazawa, N., Minami, S., Koretsune, T., Arita, R., Tarucha, S., Yamamoto, M., and Tokura, Y.:
"Topological kagome magnet Co3Sn2S2 thin flakes with high electron mobility and large anomalous Hall effect"
Nano Letters 20, 10, 7476¬–7481 (2020)
8. Fujishiro, Y., Kanazawa, N., and Tokura, Y.:
"Engineering skyrmions and emergent monopoles in topological spin crystals"
Applied Physics Letters 116, 090501 (2020)
9. Fujishiro, Y., Kanazawa, N., Nakajima, T., Yu, X. Z., Ohishi, K., Kawamura, Y., Kakurai, K., Arima, T., Mitamura, H., Miyake, A., Akiba, K., Tokunaga, M., Matsuo, A., Kindo, K., Koretsune, T., Arita, R., and Tokura, Y.:
"Topological transitions among skyrmion- and hedgehog-lattice states in cubic chiral magnets"
Nature Communications 10, 1059 (2019)
10. Fujishiro, Y., Kanazawa, N., Shimojima, T., Nakamura, A., Ishizaka, K., Koretsune, T., Arita, R., Miyake, A., Mitamura, H., Tokunaga, M., Shiogai, J., Kimura, S., Awaji, S., Tsukazaki, A., Kikkawa, A., Taguchi, Y., and Tokura, Y.:
"Large magneto-thermopower in MnGe with topological spin texture"
Nature Communications 9, 408 (2018)

Lab Members

Principal investigator

Yukako Fujishiro: RIKEN ECL Unit Leader

Contact Information

Frontier Research Laboratory
2-1 Hirosawa, Wako, Saitama 351-0198, Japan
Email: yukako.fujishiro [at] riken.jp