Chief Scientist Laboratories Nanoscale Quantum Photonics Laboratory
Chief Scientist: Yuichiro Kato (Ph.D.)
Research Summary

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
Keywords
- 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. Yamashita, N. Fang, S. Fujii, Y. K. Kato:
"Hybrid silicon all-optical switching devices integrated with 2D material"
Adv. Opt. Mater. 13, 2402531 (2025). - 2.
D. Kozawa, S. Fujii, Y. K. Kato:
"Intrinsic process for upconversion photoluminescence via K-momentum-phonon coupling in carbon nanotubes"
Phys. Rev. B 110, 155418 (2024). [Editors' Suggestion] - 3.
C. F. Fong, D. Yamashita, N. Fang, S. Fujii, Y.-R. Chang, T. Taniguchi, K. Watanabe, Y. K. Kato:
"Self-aligned hybrid nanocavities using atomically thin materials"
ACS Photonics 11, 2247 (2024). - 4.
N. Fang, Y. R. Chang, S. Fujii, D. Yamashita, M. Maruyama, Y. Gao, C. F. Fong, D. Kozawa, K. Otsuka, K. Nagashio, S. Okada, Y. K. Kato:
"Room-temperature quantum emission from interface excitons in mixed-dimensional heterostructures"
Nature Commun. 15, 2871 (2024). - 5.
S. Fujii, N. Fang, D. Yamashita, D. Kozawa, C. F. Fong, Y. K. Kato:
"van der Waals decoration of ultra-high-Q silica microcavities for χ(2)-χ(3) hybrid nonlinear photonics"
Nano Lett. 24, 4209 (2024). - 6.
N. Fang, Y. R. Chang, D. Yamashita, S. Fujii, M. Maruyama, Y. Gao, C. F. Fong, K. Otsuka, K. Nagashio, S. Okada, Y. K. Kato:
"Resonant exciton transfer in mixed-dimensional heterostructures for overcoming dimensional restrictions in optical processes"
Nature Commun. 14, 8152 (2023). - 7.
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). - 8.
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). - 9.
A. Ishii, H. Machiya, Y. K. Kato:
"High efficiency dark-to-bright exciton conversion in carbon nanotubes"
Phys. Rev. X 9, 041048 (2019). - 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
Feb. 20, 2025
How carbon nanotubes give out more than they receiveMay 25, 2021
Engineering matter at the atomic level
Annual research report
Related Links
Lab Members
Principal investigator
- Yuichiro Kato
- Chief Scientist
Core members
- Wataru Terashima
- Research Scientist
- Nan Fang
- Research Scientist
- Mengyue Wang
- Postdoctoral Researcher
- Ufuk Erkilic
- Postdoctoral Researcher
- Kenichi Cho
- Postdoctoral Researcher
- Keigo Otsuka
- Visiting Scientist
- Yih-Ren Chang
- 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@ml.riken.jp