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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. Kozawa, X. Wu, A. Ishii, J. Fortner, K. Otsuka, R. Xiang, T. Inoue, S. Maruyama, Y. Wang, Y. K. Kato:
    "Formation of organic color centers in air-suspended carbon nanotubes using vapor-phase reaction"
    Nature Commun. 13, 2814 (2022).
  • 2. H. Machiya, D. Yamashita, A. Ishii, Y. K. Kato:
    "Evidence for near-unity radiative quantum efficiency of bright excitons in carbon nanotubes from the Purcell effect"
    Phys. Rev. Research 4, L022011 (2022).
  • 3. C. F. Fong, Y. Ota, Y. Arakawa, S. Iwamoto, Y. K. Kato:
    "Chiral modes near exceptional points in symmetry broken H1 photonic crystal cavities"
    Phys. Rev. Research 3, 043096 (2021).
  • 4. Z. Li, K. Otsuka, D. Yamashita, D. Kozawa, Y. K. Kato:
    "Quantum emission assisted by energy landscape modification in pentacene-decorated carbon nanotubes"
    ACS Photonics 8, 2367 (2021).
  • 5. K. Otsuka, N. Fang, D. Yamashita, T. Taniguchi, K. Watanabe, Y. K. Kato:
    "Deterministic transfer of optical-quality carbon nanotubes for atomically defined technology"
    Nature Commun. 12, 3138 (2021).
  • 6. 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).
  • 7. A. Ishii, H. Machiya, Y. K. Kato:
    "High efficiency dark-to-bright exciton conversion in carbon nanotubes"
    Phys. Rev. X 9, 041048 (2019).
  • 8. 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).
  • 9. *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).
  • 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).

Recent Research Results

Related Links

Lab Members

Principal investigator

Yuichiro Kato
Team Leader

Core members

Daichi Kozawa
Special Postdoctoral Researcher
Daiki Yamashita
Visiting Researcher
Shun Fujii
Visiting Scientist


Position Deadline
Seeking a few Research Scientists or Postdoctoral Researchers (W22315) Open until filled
Seeking a few Postdoctoral Researchers (W22309) Open until filled

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