The MCQST Colloquium Series features interdisciplinary talks given by visiting international speakers. The monthly colloquium covers topics spanning all MCQST research units and will be broadcast live via Zoom for audiences worldwide. The main goal of the series is to create the framework for idea exchange, to strengthen links with QST leading groups worldwide, as well as to act as an integral part of the local educational environment.
MCQST Colloquium: Kenji Ohmori
We are excited to invite you to the colloquium talk by Kenji Ohmori (Institute for Molecular Science (IMS) of the National Institutes of Natural Sciences, Okazaki, Japan).
Agenda
14:00 | Teaser talk by tbd on "tbd"
14:15 | Coffee break
14:30 | Colloquium talk by Kenji Ohmorion “‘Ultrafast quantum computing with ultracold atom arrays at quantum speed limit”
Ultrafast quantum computing with ultracold atom arrays at quantum speed limit
Neutral-atom quantum computers use the arrays of ultracold atoms assembled with optical tweezers, in which each single atom serves as a high-quality qubit, whereas the whole system operates at room temperatures. My moonshot project generously supported by the Cabinet Office of Japan uses rubidium (Rb) atoms as qubits at Institute for Molecular Science (IMS) and has various core competences including ultrafast laser technologies that allow for an ultrafast two-qubit gate operating in nanoseconds, faster than any other two-qubit gates with neutral atoms by two orders of magnitude [1]. This has been made possible with two nearby ultracold Rb atoms excited simultaneously with an ultrashort laser pulse to a Rydberg state far beyond the Rydberg blockade regime [1-5]. We have also been developing underlying technologies that would improve the fidelity of this ultrafast gate, such as stable gate-operation lasers, an automated system for ultraprecise initialization of many qubits, and a super-resolution microscope using a single Rb atom as a scanning probe [6-8]. In another direction of our R&D, we develop a full-stack quantum computer at IMS with 500 qubits. This is Japan’s first full-stack quantum computer with neutral atoms, and one of only a few in the world, expected to serve as a new platform utilized by theory and software researchers for error correction protocols optimized for neutral-atom architecture, and by corporate researchers for practical use cases.
References
[1] Y. Chew et al., Nat. Photonics 16, 724 (2022). (Front Cover Highlight) [2] N. Takei et al., Nat. Commun. 7, 13449 (2016). Highlighted by Science 354, 1389 (2016); IOP PhyscisWorld.com (2016). [3] M. Mizoguchi et al., Phys. Rev. Lett. 124, 253201 (2020). [4] V. Bharti et al., Phys. Rev. Lett. 131, 123201 (2023). [5] V. Bharti et al., Phys. Rev. Lett. 133, 093405 (2024). [6] T. P. Mahesh et al., Opt. Lett. 50, 403 (2025). [7] V. Lienhard et al., Phys. Rev. Lett. 135, 253404 (2025). [8] T. Tomita et al., Nat. Commun. 17, 4727 (2026).
About Kenji Ohmori
Kenji Ohmori is a Chair Professor at the Institute for Molecular Science (IMS), National Institutes of Natural Sciences, Japan. After receiving his Ph.D. from The University of Tokyo in 1992, he was a Research Associate and an Associate Professor at Tohoku University. In 2003 he was appointed a Full Professor at IMS. Professor Ohmori is currently leading large-scale / long-term national projects on the development of ultrafast quantum simulators and quantum computers (2018-2031) generously supported with priority by the Ministry of Education, Culture, Sports, Science and Technology (MEXT) and Cabinet Office of the government of Japan. He has been celebrated with many honors. Highlights include the Japan Academy Medal (2007), Fellow of the American Physical Society (2009), Humboldt Research Award from the government of Germany (2012), Commendation for Science and Technology by the Minister of MEXT (2018), and the National Medal with Purple Ribbon from His Majesty the Emperor of Japan for his achievements on quantum physics (2021). The Medal with Purple Ribbon is awarded for inventions and discoveries in science and technology, and for outstanding achievements in the fields of science, sports, art and culture. He has served as the Chair of the “Committee for Quantum Science and Technology Policy” of MEXT from 2023-2025, after serving as the Vice Chair from 2015-2022. He is the Co-founder and Executive Advisor of Japan’s first neutral atom quantum computing startup “Yaqumo Inc.” launched on 1st April 2025.
