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Chief Scientist Laboratories Nanoscale Quantum Photonics Laboratory

Chief Scientist: Yuichiro Kato (Ph.D.)

Research Summary

Yuichiro  Kato(Ph.D.)

Control over the quantum nature of photons at the nanoscale opens up unique opportunities in quantum information processing. We study the physics underlying the operation of nanoscale photonic devices to explore new approaches for manipulating quantum states, with focus on devices that make use of individual single-walled carbon nanotubes. By combining microspectroscopy with electronic techniques, we investigate unconventional methods for manipulating the optical properties of nanomaterials within device structures, which should form the basis for future quantum technologies employing integrated quantum photonic circuits.

Main Research Fields

  • Interdisciplinary Science & Engineering

Related Research Fields

  • Mathematical & Physical Sciences
  • Chemistry
  • Engineering
  • nanostrucutre physics
  • condensed matter physics I
  • optical engineering, photon science


  • optical properties
  • nanoscale physics
  • device physics
  • 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

Annual research report

Related Links

Lab Members

Principal investigator

Yuichiro Kato
Chief Scientist

Core members

Wataru Terashima
Research Scientist
Nan Fang
Special Postdoctoral Researcher
Chee Fai Fong
Special Postdoctoral Researcher
Keigo Otsuka
Visiting Scientist

Contact Information

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