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RIKEN Center for Emergent Matter Science Emergent Device Research Group

Group Director: Yoshihiro Iwasa (D.Eng.)

Research Summary

Yoshihiro  Iwasa(D.Eng.)

Emergent Device Research Group is proposing an interdisciplinary concept “Iontronics”, which stands for ion controlled electronics. The purpose of the Emergent Device Team is to make revolutionary contribution to the creation novel properties and function of quantum matter such as strongly correlated materials and nanostructured materias. The central device is the electric double layer transistor (EDLT) using organic electrolyte or ionic liquids/gels, which enables us to produce ultrahigh electric fields or in-situ physical property measurements of the electrochemical processes, which are difficult or impossible to realize in conventional field effect transistors. With EDLT, we explore novel quantum phenomena such as electric field induced superconductivity, Mott transistor, electric field manipulation of spin current. Also, through iontronics, we aim at creating new thermoelectric materials with revolutionarily high energy conversion efficiency.

Main Research Fields

  • Mathematical & Physical Sciences

Related Research Fields

  • Interdisciplinary Science & Engineering
  • Chemistry
  • Engineering


  • Electric double layer transistor
  • Two dimensional materials
  • Collodal quantum dots
  • Thermoelectric materials
  • Superconductivity

Selected Publications

  • 1.Bisri, S. Z., Shimizu, S., Nakano, M., and Iwasa, Y.:
    "Endeavor of iontronics: from fundamentals to applications of ion-controlled electronics"
    Adv. Mater. 29, 1607054 (2017).
  • 2.Ideue, T., Hamamoto, K., Koshikawa, S., Ezawa, M., Shimizu, S., Kaneko, Y., Tokura, Y., Nagaosa, N., Iwasa, Y.:
    "Bulk rectification effect in a polar semiconductor"
    Nat. Phys. 13, 578 (2017).
  • 3.Qin, F., Shi, W., Ideue, T., Yoshida, M., Zak, A., Tenne, R., Kikitsu, T., Inoue, D., Hashizume, D., and Iwasa, Y.:
    "Superconductivity in a chiral nanotube"
    Nat. Commun. 8, 14465 (2017).
  • 4.Wakatsuki, R., Saito, Y., Hoshino, S., Itahashi, Y. M., Ideue, T., Ezawa, M., Iwasa, Y., and Nagaosa, N.:
    "Nonreciprocal charge transport in noncentrosymmetric superconductors"
    Sci. Adv. 3, e1602390 (2017).
  • 5.Yoshida, M., Iizuka, T., Suzuki, R., Zhang, Y., Iwasa, Y., and Shimizu, S.:
    "Gate-optimized thermoelectric power factor in ultrathin WSe2 single crystals"
    Nano Lett. 16, 2016 (2016).
  • 6.Saito, Y., Nakamura, Y., Bahramy, M. S., Kohama, Y., Ye, J. T., Kasahara, Y., Nakagawa, Y., Onga, M., Tokunaga, M., Nojima, T., Yanase, Y., and Iwasa, Y.:
    "Superconductivity protected by spin–valley locking in ion-gated MoS2"
    Nat. Phys. 12, 144 (2016).
  • 7.Shimizu, S., Bahramy, M. S., Iizuka, T., Ono, S.,, Miwa, K., Tokura, Y., and Iwasa, Y.:
    "Enhanced thermopower in ZnO two-dimensional electron gas"
    PNAS 113, 6438 (2016).
  • 8.Shimizu, S., Ono, S., Hatano, T., Iwasa, T., and Tokura, Y.:
    "Enhanced cryogenic thermopower in SrTiO3 by ionic gating"
    Phys. Rev. B 92, 165304 (2015).
  • 9.Nii., Y., Nakajima, T., Kikkawa, A., Yamasaki, Y., Ohishi, K. Suzuki, J. Taguchi, Y., Arima, T., Tokura, Y., and Iwasa, Y.:
    "Uniaxial stress control of skyrmion phase"
    Nat. Commun. 6, 8539 (2015).
  • 10.Suzuki, R., Sakano, M. Zhang, Y. J., Akashi, R., Morikawa, D., Harasawa, A., Yaji, K., Kuroda, K., Miyamoto, K., Okuda, T., Ishizaka, K., and Iwasa, Y.:
    "Valley-dependent spin polarization in bulk MoS2 with broken inversion symmetry"
    Nat. Nanotech. 9, 611 (2014).

Recent Research Results

Related Links

Lab Members

Principal investigator

Yoshihiro Iwasa
Group Director

Core members

Hideki Matsuoka
Special Postdoctoral Researcher
Ricky Dwi Septianto
Postdoctoral Researcher
Satria Bisri
Visiting Scientist
Sunao Shimizu
Visiting Scientist
Nan Jiang
Visiting Scientist
Yuki Itahashi
Visiting Scientist
Retno Dwi Wulandari
International Program Associate
Thanyarat Phutthaphongloet
International Program Associate
Alec Paul Romagosa
International Program Associate

Contact Information

2-1 Hirosawa, Wako, Saitama 351-0198, Japan
Tel: +81-(0)48-467-8083
Email: iwasay [at] riken.jp