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Chief Scientist Laboratories Nanoscale Quantum Photonics Laboratory

Chief Scientist: Yuichiro Kato (Ph.D.)

Research Summary

Yuichiro  Kato(Ph.D.)

Quantum technologies are expected to make important developments in various fields of engineering including computing, sensing, metrology, and communication. Since quantum effects become more evident and more robust as the system scales down, devices with atomically precise elements could provide a route for quantum technologies operating at elevated temperatures. Our research focuses on the optical properties of nanomaterials and the physics of nanoscale photonic devices, investigating new approaches for utilizing their quantum properties. By engineering atomically defined nanostructures and integrating them into nanoscale devices, we explore novel concepts in photonics for future quantum technologies.

Main Research Fields

  • Interdisciplinary Science & Engineering

Related Research Fields

  • Mathematical & Physical Sciences
  • Chemistry
  • Engineering
  • nanostrucutre physics
  • optical engineering and 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.N. Fang, D. Yamashita, S. Fujii, K. Otsuka, T. Taniguchi, K. Watanabe, K. Nagashio, Y. K. Kato:
    "Quantization of mode shifts in nanocavities integrated with atomically thin sheets"
    Adv. Opt. Mater. 10, 2200538 (2022).
  • 2.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).
  • 3.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).
  • 4.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).
  • 5.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).
  • 6.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).
  • 7.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).
  • 8.A. Ishii, H. Machiya, Y. K. Kato:
    "High efficiency dark-to-bright exciton conversion in carbon nanotubes"
    Phys. Rev. X 9, 041048 (2019).
  • 9.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).
  • 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
Chee Fai Fong
Special Postdoctoral Researcher
Yih-Ren Chang
Visiting Researcher
Keigo Otsuka
Visiting Scientist
Nan Fang
Visiting Scientist

Contact Information

Room 410, Main Research Building,
2-1 Hirosawa,
Wako, Saitama
351-0198, Japan
Tel: +81-(0)48-462-1449
Email: katogp-info [at] ml.riken.jp