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RIKEN Center for Advanced Photonics Quantum Optoelectronics Research Team

Team Leader: Yuichiro Kato (Ph.D.)

Research Summary

Yuichiro  Kato(Ph.D.)

Advances in device fabrication techniques have enabled integration of individual nanomaterials, where single electrons and single photons could be addressed. We exploit state-of-the-art nanofabrication technologies to develop and engineer optoelectronic devices with novel functionalities that can only be achieved by utilizing the quantum nature of electrons and photons at the nanoscale. We investigate devices that would allow for control over the interactions between electrons and photons at the quantum mechanical level, which would lead to quantum photon sources and optical-to-electrical quantum interfaces.

Main Research Fields

  • Interdisciplinary Science & Engineering

Related Research Fields

  • Mathematical & Physical Sciences
  • Chemistry
  • Engineering


  • optoelectronics
  • quantum devices
  • nanoscale devices
  • carbon nanotubes
  • photonic crystals

Selected Publications

Papers with an asterisk(*) are based on research conducted outside of RIKEN.

  • 1. D. Yamashita, H. Machiya, K. Otsuka, A. Ishii, Y. K. Kato.:
    "Waveguide coupled cavity-enhanced light emission from individual carbon nanotubes"
    APL Photonics 6, 031302 (2021).
  • 2. N. Fang, K. Otsuka, A. Ishii, T. Taniguchi, K. Watanabe, K. Nagashio, Y. K. Kato.:
    "Hexagonal boron nitride as an ideal substrate for carbon nanotube photonics"
    ACS Photonics 7, 1773 (2020).
  • 3. A. Ishii, H. Machiya, Y. K. Kato.:
    "High efficiency dark-to-bright exciton conversion in carbon nanotubes"
    Phys. Rev. X 9, 041048 (2019).
  • 4. K. Otsuka, A. Ishii, Y. K. Kato.:
    "Super-resolution fluorescence imaging of carbon nanotubes using a nonlinear excitonic process"
    Opt. Express 27, 17463 (2019).
  • 5. S. Tanaka, K. Otsuka, K. Kimura, A. Ishii, H. Imada, Y. Kim, Y. K. Kato.:
    "Organic molecular tuning of many-body interaction energies in air-suspended carbon nanotubes"
    J. Phys. Chem. C 123, 5776 (2019).
  • 6. A. Ishii, X. He, N. F. Hartmann, H. Machiya, H. Htoon, S. K. Doorn, Y. K. Kato.:
    "Enhanced single photon emission from carbon nanotube dopant states coupled to silicon microcavities"
    Nano Lett. 18, 3873 (2018).
  • 7. A. Ishii, T. Uda, Y. K. Kato.:
    "Room-temperature single-photon emission from micrometer-long air-suspended carbon nanotubes"
    Phys. Rev. Applied 8, 054039 (2017).
  • 8. *R. Miura, S. Imamura, R. Ohta, A. Ishii, X. Liu, T. Shimada, S. Iwamoto, Y. Arakawa, Y. K. Kato.:
    "Ultralow mode-volume photonic crystal nanobeam cavities for high-efficiency coupling to individual carbon nanotube emitters"
    Nature Commun. 5, 5580 (2014).
  • 9. *S. Moritsubo, T. Murai, T. Shimada, Y. Murakami, S. Chiashi, S. Maruyama, Y. K. Kato.:
    "Exciton diffusion in air-suspended single-walled carbon nanotubes"
    Phys. Rev. Lett. 104, 247402 (2010).
  • 10. *Y. K. Kato, R. C. Myers, A. C. Gossard, D. D. Awschalom.:
    "Observation of the spin Hall effect in semiconductors"
    Science 306, 1910 (2004).

Related Links

Lab Members

Principal investigator

Yuichiro Kato
Team Leader

Core members

Daichi Kozawa
Special Postdoctoral Researcher
Shun Fujii
Special Postdoctoral Researcher
Zhen Li
Special Postdoctoral Researcher
Daiki Yamashita
Visiting Researcher

Contact Information

Main Research Building, Room 420,
2-1 Hirosawa,
Wako, Saitama
351-0198, Japan
Tel: +81-(0)48-462-1449
Email: katogp-info [at] ml.riken.jp