1. Home
  2. Research
  3. Centers & Labs
  4. Chief Scientist Laboratories etc

Chief Scientist Laboratories Advanced Device Laboratory

Chief Scientist: Koji Ishibashi (D.Eng.)

Research Summary

Koji  Ishibashi(D.Eng.)

We study physics in nanoscale structures that are fabricated with carbon nanotubes and semiconductor nanowires as well as nanoscale Si transistors. By controlling the quantum state of electrons, spins, and excitons one by one, we try to realize quantum information devices. On top of that, we study interesting physics in topological insulator/superconductor hybrid structures and hope to apply for the topological quantum bits.

Main Research Fields

  • Engineering

Related Research Fields

  • Interdisciplinary Science & Engineering
  • Mathematical & Physical Sciences
  • Nano/Microscience
  • Applied physics


  • Quantum nanoscale devices
  • Topological insulator/superconductor hybrid structures
  • Carbon nanotubes
  • Semiconductor nanowires
  • Nanoscale Si transistors

Selected Publications

  • 1. Rui Wang, Russell S. Deacon, Jian Sun, Jun Yao, Charles M. Lieber, Koji Ishibashi.:
    "Gate Tunable Hole Charge Qubit Formed in a Ge/Si Nanowire Double Quantum Dot Coupled to Microwave Photons"
    Nano Letters 19, 1052 (2019)
  • 2. Keiji Ono, Takahiro Mori, Satoshi Moriyama.:
    "High-temperature operation of a silicon qubit"
    Scientific Report, 9, 469 (2019)
  • 3. Jian Sun, Russell Deacon, Rui Wang, Jun Yao, Charles M. Lieber, Koji Ishibashi.:
    "Helical Hole State in Multiple Conduction Modes in Ge/Si Core/Shell Nanowire"
    Nano Letters 18, 6144 (2018)
  • 4. Masashi Nantoh, Kengo Takashima, Takahiro Yamamoto and Koji Ishibashi.:
    "Sublattice site dependence of local electronic states in superstructures of CO built on a Cu(111) surface"
    Physical Review B 96, 035424 (2017)
  • 5. Russell Deacon, Jonas Wiedenmann, Erwann Bocquillon, Teun M. Klapwijk, Philipp Leubner, Christoph Brüne, Seigo Tarucha, Koji Ishibashi, Hartmut Buhmann, Laurens W. Molenkamp.:
    "Josephson radiation from gapless Andreev bound states in HgTe-based topological junctions"
    Physical Review X 7, 021011 (2017)
  • 6. Erwann Bocquillon, Russell Deacon, Jonas Wiedenmann, Philipp Leubner, Teun M. Klapwijk, Christoph Brüne, Koji Ishibashi, H. Buhmann, Laurens W. Molenkamp.:
    "Gapless Andreev bound states in the quantum spin Hall insulator HgTe"
    Nature Nanotechnology, 12, 137 (2017)
  • 7. Hiroshi Tomizawa, Katsuya Suzuki, Tomohiro Yamaguchi, Seiji Akita and Koji Ishibashi.:
    "Control of tunnel barriers in multi-wall carbon nanotubes using focused ion beam irradiation"
    Nanotechnology, 28, 165302 (2017)
  • 8. Akira Hida and Koji Ishibashi.:
    "Molecule-induced quantum confinement in single-walled carbon nanotube"
    Appl. Phys. Express 8, 045101 (2015)
  • 9. Y. Kawano, T. Fuse, S. Toyokawa, T. Uchida, K. Ishibashi.:
    "Terahertz photon-assisted tunneling in carbon nanotube quantum dots"
    Journal of Applied Physics 103, 034307 (2008)
  • 10. S. Moriyama, T. Fuse, M. Suzuki, Y. Aoyagi, K. Ishibashi.:
    "Four-electron shell structures and an interacting two-electron system in carbon nanotube quantum dots"
    Physical Review Letters 94, 186806 (2005)

Recent Research Results

Annual research report

Related Links

Lab Members

Principal investigator

Koji Ishibashi
Chief Scientist

Core members

Tomohiro Yamaguchi
Senior Research Scientist
Masashi Nantoh
Senior Research Scientist
Keiji Ono
Senior Research Scientist
Russell Stewart Deacon
Senior Research Scientist
Akira Hida
Research Scientist
Yoshisuke Ban
Postdoctoral Researcher
Hui Wang
Contract Researcher
Takayuki Okamoto
Special Temporary Research Scientist
Masayuki Hosoda
Visiting Scientist

Contact Information

2-1 Hirosawa, Wako, Saitama 351-0198, Japan
Email: kishiba [at] riken.jp