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YAMAGAMI Tomoki
| Mathematics, Electronics and Informatics Division | Assistant Professor |
| Department of Information and Computer Sciences |
- Researcher Profile:
Updates of this page are summarized here (in Japanese).
- E-Mail：tyamagami
mail.saitama-u.ac.jp - Home Page:
Researcher information
■ Degree- Bachelor of Science, Yokohama National University
Mar. 2019 - Master of Science, Yokohama National University
Mar. 2021 - Doctor of Philosophy in the field of Information Science and Technology, The University of Tokyo
Mar. 2024
■ Career
- Apr. 2025 - Present, Saitama University, Graduate School of Science and Engineering, Assistant Professor
- Apr. 2024 - Mar. 2025, Yokohama National University, College of Engineering Science, Part-time lecturer
- Apr. 2024 - Mar. 2025, Japan Society for the Promotion of Science, Research Fellowship for Young Scientists (PD)
- Apr. 2023 - Mar. 2024, Japan Society for the Promotion of Science, Research Fellowship for Young Scientists (DC2), Japan
- Oct. 2021 - Mar. 2024, The University of Tokyo
- Apr. 2021 - Mar. 2024, The University of Tokyo, The Graduate School of Information Science and Technology, Department of Information Physics and Computing, Japan
- Apr. 2019 - Mar. 2021, Yokohama National University, Graduate school of Engineering Science, Department of Mathematics, Electrical Engineering and Computer Science, Japan
- Apr. 2015 - Mar. 2019, Yokohama National University, College of Engineering Science, Department of Mathematics, Physics, Electrical Engineering and Computer Science, Japan
■ Award
- Nov. 2024, Best Student Paper Award, Conflict avoidance in two-walker quantum walk through entanglement, International Symposium on Physics and Applications of Laser Dynamics 2024 (IS-PALD 2024)
H. Shiratori;A. Röhm;T. Yamagami;E. Segawa;T. Mihana;R. Horisaki, International society, Japan - Mar. 2024, Dean's Award of the Graduate School of Information Science and Technology, Quantum Walk and Its Application to Decision-Making, The University of Tokyo
Others, Japan - Dec. 2022, Student Paper Award, Skeleton Structure Inherent in Quantum Walks, 2022 International Symposium on Nonlinear Theory and Its Applications (NOLTA 2022)
Tomoki Yamagami, International society - Dec. 2021, Student Presentation Award, Generation of one-dimensional random walks driven by quantum walks, 2021 International Conference on Emerging Technologies for Communications (ICETC 2021)
Tomoki Yamagami, International society
Performance information
■ Paper- Two-dimensional Beam Selection by Multi-armed Bandit Algorithm based on a Quantum Walk
Maki Arai; Tomoki Yamagami; Takatomo Mihana; Ryoichi Horisaki; Mikio Hasegawa
IEEE Transactions on Quantum Engineering, Volume：6, First page：3100916, Mar. 2025, [Reviewed]
Institute of Electrical and Electronics Engineers (IEEE), Scientific journal
DOI：https://doi.org/10.1109/tqe.2025.3555145
DOI ID：10.1109/tqe.2025.3555145, eISSN：2689-1808 - Asymmetric quantum decision-making
Honoka Shiratori; Hiroaki Shinkawa; André Röhm; Nicolas Chauvet; Etsuo Segawa; Jonathan Laurent; Guillaume Bachelier; Tomoki Yamagami; Ryoichi Horisaki; Makoto Naruse
Scientific Reports, Volume：13, Number：1, First page：14636, Sep. 2023, [Reviewed], ［Internationally co-authored］
Abstract
Collective decision-making plays a crucial role in information and communication systems. However, decision conflicts among agents often impede the maximization of potential utilities within the system. Quantum processes have shown promise in achieving conflict-free joint decisions between two agents through the entanglement of photons or the quantum interference of orbital angular momentum (OAM). Nonetheless, previous studies have shown symmetric resultant joint decisions, which, while preserving equality, fail to address disparities. In light of global challenges such as ethics and equity, it is imperative for decision-making systems to not only maintain existing equality but also address and resolve disparities. In this study, we investigate asymmetric collective decision-making theoretically and numerically using quantum interference of photons carrying OAM or entangled photons. We successfully demonstrate the realization of asymmetry; however, it should be noted that a certain degree of photon loss is inevitable in the proposed models. We also provide an analytical formulation for determining the available range of asymmetry and describe a method for obtaining the desired degree of asymmetry.
Springer Science and Business Media LLC, Scientific journal
DOI：https://doi.org/10.1038/s41598-023-41715-z
DOI ID：10.1038/s41598-023-41715-z, eISSN：2045-2322 - Bandit Algorithm Driven by a Classical Random Walk and a Quantum Walk
Tomoki Yamagami; Etsuo Segawa; Takatomo Mihana; André Röhm; Ryoichi Horisaki; Makoto Naruse
Entropy, Volume：25, Number：6, First page：843, May 2023, [Reviewed], [Lead, Corresponding]
Scientific journal
DOI：https://doi.org/10.3390/e25060843
DOI ID：10.3390/e25060843, ORCID：135766120 - Information-theoretical analysis of statistical measures for multiscale dynamics
Naoki Asuke; Tomoki Yamagami; Takatomo Mihana; André Röhm; Ryoichi Horisaki; Makoto Naruse
Chaos: An Interdisciplinary Journal of Nonlinear Science, Volume：33, Number：4, First page：043138, Apr. 2023, [Reviewed]
Scientific journal
DOI：https://doi.org/10.1063/5.0141099
DOI ID：10.1063/5.0141099, ORCID：133899975 - Skeleton structure inherent in discrete-time quantum walks
Tomoki Yamagami; Etsuo Segawa; Ken'ichiro Tanaka; Takatomo Mihana; André Röhm; Ryoichi Horisaki; Makoto Naruse
Physical Review A, Volume：107, Number：1, First page：012222, Jan. 2023, [Reviewed], [Lead, Corresponding]
Scientific journal
DOI：https://doi.org/10.1103/PhysRevA.107.012222
DOI ID：10.1103/PhysRevA.107.012222, ORCID：127742067 - Directivity of Quantum Walk via Its Random Walk Replica
Tomoki Yamagami; Etsuo Segawa; Nicolas Chauvet; André Röhm; Ryoichi Horisaki; Makoto Naruse
Complexity, Volume：2022, First page：9021583, Oct. 2022, [Reviewed], [Lead, Corresponding]
Scientific journal
DOI：https://doi.org/10.1155/2022/9021583
DOI ID：10.1155/2022/9021583, ORCID：121721716 - Theory of Acceleration of Decision-Making by Correlated Time Sequences
Norihiro Okada; Tomoki Yamagami; Nicolas Chauvet; Yusuke Ito; Mikio Hasegawa; Makoto Naruse
Complexity, Volume：2022, First page：5205580, Aug. 2022, [Reviewed]
Scientific journal
DOI：https://doi.org/10.1155/2022/5205580
DOI ID：10.1155/2022/5205580, ORCID：117908600 - General condition of quantum teleportation by one-dimensional quantum walks
Tomoki Yamagami; Etsuo Segawa; Norio Konno
Quantum Information Processing, Volume：20, Number：7, First page：224, Jul. 2021, [Reviewed], [Lead, Corresponding]
Springer Science and Business Media {LLC}, English, Scientific journal
DOI：https://doi.org/10.1007/s11128-021-03155-4
DOI ID：10.1007/s11128-021-03155-4, ISSN：1570-0755, ORCID：126770619
- 2025年度 東京大学 工学部計数工学科システム情報学コース／大学院情報理工学系研究科システム情報学専攻 パンフレット（寄稿）
01 Apr. 2025 - A study of the Antlion Random Walk
Akihiro Narimatsu; Tomoki Yamagami
arXiv Preprint, 17 Mar. 2025
DOI：https://doi.org/10.48550/arXiv.2503.12775
DOI ID：10.48550/arXiv.2503.12775 - Normal variance mixture with arcsine law of an interpolating walk between persistent random walk and quantum walk
Saori Yoshino; Honoka Shiratori; Tomoki Yamagami; Ryoichi Horisaki; Etsuo Segawa
arXiv Preprint, 04 Mar. 2025
DOI：https://doi.org/10.48550/arXiv.2503.03021
DOI ID：10.48550/arXiv.2503.03021
- 教師なし学習によるシングルモードレーザのダイナミクス調査
前田 紘希; 巳鼻 孝朋; 山上 智輝; アンドレ レーム; 堀崎 遼一
Jun. 2025, [Domestic conference]
Jun. 2025 - Jun. 2025, Japan - 量子ウォークを用いたグラフ上の最適腕識別アルゴリズム
山上 智輝; 瀬川 悦生; 巳鼻 孝朋; レーム アンドレ; 内田 淳史; 堀﨑 遼一
Jun. 2025, [Domestic conference]
Jun. 2025 - Jun. 2025, Oral presentation, Japan - 光電気リザーバコンピューティングのデジタルツインの作成
関口 雄太郎; レーム アンドレ; 巳鼻 孝朋; 山上 智輝; 菅野 円隆; 堀﨑 遼一
Mar. 2025, [Domestic conference]
Mar. 2025 - Mar. 2025 - 量子ウォーク探索によるグラフ上における最適腕識別
山上 智輝; 瀬川 悦生; レーム アンドレ; 巳鼻 孝朋; 堀﨑 遼一
Feb. 2025, [Domestic conference]
Feb. 2025, Japanese, Oral presentation, Japan - グラフ上の最適腕識別問題に対する量子ウォーク探索アルゴリズム
山上 智輝
Jan. 2025, [Invited]
Jan. 2025 - 量子ウォーク探索によるグラフ上の最適腕識別
山上 智輝
Dec. 2024, [Invited]
Dec. 2024, Japan - 確率過程モデルを用いた負の自己相関を持つ時系列による意思決定加速に関する考察
山上 智輝; 長谷川 幹雄; 巳鼻 孝朋; 堀﨑 遼一
Dec. 2024, [Domestic conference]
Dec. 2024, Japanese, Poster presentation - 量子ウォークに基づくMABアルゴリズムを用いた高速ビーム選択に関する研究
新井 麻希; 山上 智輝; 巳鼻 孝朋; 堀﨑 遼一; 長谷川 幹雄
Dec. 2024, [Domestic conference]
Dec. 2024, Japanese, Poster presentation - Stochastic Process Model for Photonic Decision-Maker
Tomoki Yamagami; Mikio Hasegawa; Takatomo Mihana; Ryoichi Horisaki
2024 International Symposium on Nonlinear Theory and Its Applications (NOLTA 2024), Dec. 2024, [International conference]
Dec. 2024 - Dec. 2024, Oral presentation, Ha Long, Viet Nam - Stochastic process model for decision-making acceleration by negatively autocorrelated time sequences
Tomoki Yamagami; Mikio Hasegawa; Takatomo Mihana; Ryoichi Horisaki
International Symposium on Physics and Applications of Laser Dynamics 2024 (IS-PALD 2024), Nov. 2024, [International conference]
Nov. 2024 - Nov. 2024, Oral presentation, Saitama, Japan
Selected as an oral presentation by the peer review - Conflict avoidance in two-walker quantum walk through entanglement
Honoka Shiratori; André Röhm; Tomoki Yamagami; Etsuo Segawa; Takatomo Mihana; Ryoichi Horisaki
International Symposium on Physics and Applications of Laser Dynamics 2024 (IS-PALD 2024), Nov. 2024, [International conference]
Nov. 2024 - Nov. 2024, Poster presentation, Saitama, Japan - A study on optimal beam selection using a multi-armed bandit algorithm based on a five-state quantum walk
Maki Arai; Tomoki Yamagami; Takatomo Mihana; Ryoichi Horisaki; Mikio Hasegawa
International Symposium on Physics and Applications of Laser Dynamics 2024 (IS-PALD 2024), Nov. 2024, [International conference]
Nov. 2024 - Nov. 2024, Poster presentation, Saitama, Japan - 量子ウォーク探索による空間構造を持つ環境における最適腕識別
山上 智輝; 瀬川 悦生; 巳鼻 孝朋; レーム アンドレ; 成瀬 誠; 堀﨑 遼一
Sep. 2024, [Domestic conference]
Sep. 2024 - Sep. 2024, Japanese, Poster presentation - Analyses of antlion random walks
Tomoki Yamagami; Akihiro Narimatsu
MSJ Autumn Meeting 2024, Sep. 2024, [Domestic conference]
Sep. 2024 - Sep. 2024, Oral presentation, Japan - 確率過程を用いた自己相関を持つ時系列による意思決定の数理モデル
山上 智輝; 岡田 典大; 巳鼻 孝朋; 堀﨑 遼一; 成瀬 誠; 長谷川 幹雄
Jun. 2024, [Domestic conference]
Jun. 2024 - Jun. 2024, Japanese, Oral presentation, Japan - エンタングルメントに基づく競合のない量子ウォーク
白鳥 帆香; レーム アンドレ; 山上 智輝; 瀬川 悦生; 巳鼻 孝朋; 堀﨑 遼一
Jun. 2024, [Domestic conference]
Jun. 2024 - Jun. 2024, Japanese, Oral presentation, Japan - Quantum walk search as an application to best-arm identification
T. Yamagami
RIMS workshop (Group A) Studies on long time behavior for quantum walks, Nov. 2023, [Invited]
Invited oral presentation - Spatial best-arm identification via quantum walk search
Tomoki Yamagami; Etsuo Segawa; Takatomo Mihana; André Röhm; Ryoichi Horisaki; Makoto Naruse
10th International Workshop of Quantum Simulation and Quantum Walks (QSQW 2023), Nov. 2023, [International conference]
Poster presentation, Tsukuba, Japan - Quantum-Walk-Based Bandit Algorithm and its Performance
Tomoki Yamagami; Etsuo Segawa; Takatomo Mihana; André Röhm; Ryoichi Horisaki; Makoto Naruse
2023 International Symposium on Nonlinear Theory and Its Applications (NOLTA 2023), Sep. 2023, [International conference]
Oral presentation, Catania, Italy - 量子ウォーク探索を用いた空間的最適腕識別とその解析
山上 智輝
Aug. 2023, [Invited]
Oral presentation - 量子ウォークを用いたバンディットアルゴリズム
山上 智輝; 瀬川 悦生; 巳鼻 孝朋; André Röhm; 堀﨑 遼一; 成瀬 誠
Aug. 2023
Poster presentation - Quantum Walk and Its Application
Tomoki Yamagami
Quantum Optics and Decision Making Workshop, Feb. 2023, [International conference]
Oral presentation, Grenoble, France - Bandit Algorithm via Quantum Walk
Tomoki Yamagami; André Röhm; Takatomo Mihana; Ryoichi Horisaki; Makoto Naruse; Etsuo Segawa
The 9th Japan-Korea Joint Workshop on Complex Communication Sciences (JKCCS 2023), Jan. 2023, [International conference]
Oral presentation, Gyeongju, Korea, Republic of - 離散時間１次元量子ウォークの骨格構造について
山上 智輝; 瀬川 悦生; 巳鼻 孝朋; Röhm Andre; 堀﨑 遼一; 成瀬 誠
Dec. 2022
Oral presentation - Correlated Random Walk Model for Decision Making Acceleration by Time-Correlated Time Sequences
Tomoki Yamagami; Norihiro Okada; Yusuke Ito; Mikio Hasegawa; Makoto Naruse
2022 International Symposium on Nonlinear Theory and Its Applications (NOLTA 2022), Dec. 2022
Oral presentation, online - Skeleton structure inherent in quantum walks
Tomoki Yamagami; Etsuo Segawa; Ken'ichiro Tanaka; Takatomo Mihana; André Röhm; Ryoichi Horisaki; Makoto Naruse
2022 International Symposium on Nonlinear Theory and Its Applications (NOLTA 2022), Dec. 2022
Oral presentation, online
Student Paper Award - How can we improve game theory systems with quantum optics?
Jonathan Laurent; Guillaume Bachelier; Nicolas Chauvet; Makoto Naruse; Hiroaki Shinkawa; Tomoki Yamagami; Honoka Shiratori
Quantum 2022 Summer School on Quantum Optical Technologies in Apulia, Sep. 2022, [International conference]
Poster presentation, Trani, Italy - 量子ウォークを再現するランダムウォークの推移確率の骨格構造
山上 智輝; 瀬川 悦生; 巳鼻 孝朋; レーム アンドレ; 堀﨑 遼一; 成瀬 誠
Jun. 2022
Oral presentation - 量子ウォークを用いたバンディットアルゴリズム
山上 智輝; 瀬川 悦生; Nicolas Chauvet; André Röhm; 堀﨑 遼一; 成瀬 誠
Mar. 2022
Oral presentation - Generation of one-dimensional random walks driven by quantum walks
Tomoki Yamagami; Etsuo Segawa; Nicolas Chauvet; André Röhm; Ryoichi Horisaki; Makoto Naruse
2021 International Conference on Emerging Technologies for Communications (ICETC 2021), Dec. 2021
Oral presentation, online
Student Presentation Award - 量子ウォークにより駆動される1次元ランダムウォークの構成
山上 智輝; 瀬川 悦生; Nicolas Chauvet; André Röhm; 堀﨑 遼一; 成瀬 誠
Sep. 2021
Oral presentation - 1 次元量子ウォークによる量子テレポーテーションの条件
山上 智輝
May 2021, [Invited]
Invited oral presentation - 1次元格子上の量子ウォークを用いた量子テレポーテーションの研究
山上 智輝; 瀬川 悦生; 今野 紀雄
Sep. 2020
Oral presentation
- Oct. 2025
Basic Electromagnetism, Saitama University - Oct. 2025
Programming Exercise I, Saitama University - Oct. 2024 - Mar. 2025
Linear Algebra II, Yokohama National University - Apr. 2024 - Sep. 2024
Exercises in Mathematics, Yokohama National University - Apr. 2024 - Sep. 2024
Linear Algebra I, Yokohama National University
- Oct. 2024 - Present, The Mathematical Society of Japan
- Aug. 2021 - Present, The Institute of Electronics, Information and Communication Engineers
- 量子ウォークによる意思決定機構の物理的実装とその応用展開
01 Apr. 2025 - 31 Mar. 2028
Grant amount(Total)：4810000, Direct funding：3700000, Indirect funding：1110000
Grant number：25K21294 - 量子ウォークによる量子バンディットアルゴリズムの創成
Apr. 2023 - Mar. 2025
Grant amount(Total)：1800000, Direct funding：1800000
Grant number：23KJ0384