Yamamoto, Naoki

写真a

Affiliation

Faculty of Science and Technology, Department of Applied Physics and Physico-Informatics (Yagami)

Position

Professor

Related Websites

Career 【 Display / hide

  • 2003.04
    -
    2007.03

    日本学術振興会, 特別研究員

  • 2004.07
    -
    2007.02

    California Institute of Technology, Department of Physics, Postdoctral Fellow

  • 2007.04
    -
    2008.03

    Australian National University, Department of Engineering, Postdoctral Fellow

  • 2008.04
    -
    2011.03

    慶應義塾大学, 理工学部・物理情報工学科, 専任講師

  • 2011.04
    -
    Present

    慶應義塾大学, 理工学部・物理情報工学科, 准教授

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Academic Background 【 Display / hide

  • 1999.03

    The University of Tokyo, Faculty of Engineering, 計数工学科

    東京都文京区本郷7-3-1, University, Graduated

  • 2004.03

    The University of Tokyo, 情報理工学系研究科, システム情報学専攻

    東京都文京区本郷7-3-1, Graduate School, Completed, Doctoral course

Academic Degrees 【 Display / hide

  • 情報理工学, The University of Tokyo, Coursework, 2004.03

 

Research Areas 【 Display / hide

  • Atomic/Molecular/Quantum electronics

  • Control engineering/System engineering

Research Keywords 【 Display / hide

  • Quantum control

  • Quantum information

 

Books 【 Display / hide

  • Linear Dynamical Quantum Systems: Analysis, Synthesis, and Control

    H. I. Nurdin and N. Yamamoto, Springer, 2017.05

  • 複素関数論の基礎

    YAMAMOTO Naoki, 裳華房, 2015.11

Papers 【 Display / hide

  • Cascade and locally dissipative realizations of linear quantum systems for pure Gaussian state covariance assignment

    S. Ma, M. J. Woolley, I. R. Petersen, and N. Yamamoto

    Automatica 90   263 - 270 2018.02

    Research paper (scientific journal), Joint Work, Accepted,  ISSN  0005-1098

     View Summary

    <p>This paper presents two realizations of linear quantum systems for covariance assignment corresponding to pure Gaussian states. The first one is called a cascade realization; given any covariance matrix corresponding to a pure Gaussian state, we can construct a cascaded quantum system generating that state. The second one is called a locally dissipative realization; given a covariance matrix corresponding to a pure Gaussian state, if it satisfies certain conditions, we can construct a linear quantum system that has only local interactions with its environment and achieves the assigned covariance matrix. Both realizations are illustrated by examples from quantum optics.</p>

  • Dissipative-dissipative control strategy for quantum coherent feedback

    Y. Kashiwamura and N. Yamamoto

    Proceedings of IFAC World Congress    11760 - 11763 2017.12

    Research paper (international conference proceedings), Joint Work, Accepted

  • Entanglement-assisted quantum feedback control

    N. Yamamoto and T. Mikami

    Quantum Information Processing 16 ( 7 ) 179 2017.07

    Research paper (scientific journal), Joint Work, Accepted,  ISSN  1570-0755

     View Summary

    <p>The main advantage of quantum metrology relies on the effective use of entanglement, which indeed allows us to achieve strictly better estimation performance over the standard quantum limit. In this paper, we propose an analogous method utilizing entanglement for the purpose of feedback control. The system considered is a general linear dynamical quantum system, where the control goal can be systematically formulated as a linear quadratic Gaussian control problem based on the quantum Kalman filtering method; in this setting, an entangled input probe field is effectively used to reduce the estimation error and accordingly the control cost function. In particular, we show that, in the problem of cooling an opto-mechanical oscillator, the entanglement-assisted feedback control can lower the stationary occupation number of the oscillator below the limit attainable by the controller with a coherent probe field and furthermore beats the controller with an optimized squeezed probe field.</p>

  • Pure Gaussian states from quantum harmonic oscillator chains with a single local dissipative process

    S. Ma, M. J. Woolley, I. R. Petersen, and N. Yamamoto

    Journal of Physics A: Mathematical and Theoretical 50 ( 13 )  2017.02

    Research paper (scientific journal), Joint Work, Accepted,  ISSN  1751-8113

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    <p>We study the preparation of entangled pure Gaussian states via reservoir engineering. In particular, we consider a chain consisting of (2N + 1) quantum harmonic oscillators where the central oscillator of the chain is coupled to a single reservoir. We then completely parametrize the class of (2N + 1)-mode pure Gaussian states that can be prepared by this type of quantum harmonic oscillator chain. This parametrization allows us to determine the steady-state entanglement properties of such quantum harmonic oscillator chains.</p>

  • Optimal control for perfect state transfer in linear quantum memory

    H. Nakao and N. Yamamoto

    Journal of Physics B: Atomic, Molecular and Optical Physics 50 ( 6 )  2017.02

    Research paper (scientific journal), Joint Work, Accepted,  ISSN  0953-4075

     View Summary

    <p>A quantum memory is a system that enables transfer, storage, and retrieval of optical quantum states by ON/OFF switching of the control signal in each stage of the memory. In particular, it is known that, for perfect transfer of a single-photon state, appropriate shaping of the input pulse is required. However, in general, such a desirable pulse shape has a complicated form, which would be hard to generate in practice. In this paper, for a wide class of linear quantum memory systems, we develop a method that reduces the complexity of the input pulse shape of a single photon while maintaining the perfect state transfer. The key idea is twofold; (i) the control signal is allowed to vary continuously in time to introduce an additional degree of freedom, and then (ii) an optimal control problem is formulated to design a simple-formed input pulse and the corresponding control signal. Numerical simulations are conducted for Λ-type atomic media and networked atomic ensembles, to show the effectiveness of the proposed method.</p>

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Papers, etc., Registered in KOARA 【 Display / hide

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Reviews, Commentaries, etc. 【 Display / hide

  • 連続時間カルマンフィルタと量子状態推定

    山本 直樹

    計測自動制御学会誌 56 ( 9 ) 662 - 667 2017.09

    Introduction and explanation (scientific journal)

  • 量子フィードバック制御のための推定論とその応用

    山本 直樹

    京都大学数理解析研究所講究録 1834 ( 5 ) 96 - 108 2013.05

    Introduction and explanation (bulletin of university, research institution), Single Work

  • 量子フィードバック制御の数理

    山本 直樹

    数理科学 585   21 - 27 2012.03

    Introduction and explanation (commerce magazine), Single Work

  • 確率微分方程式の基礎

    山本 直樹

    計測と制御 50 ( 11 ) 937-943 2011.11

    Introduction and explanation (scientific journal), Single Work

  • 量子力学と確率システム理論

    山本 直樹

    計測と制御 50 ( 11 ) 993-999 2011.11

    Introduction and explanation (scientific journal), Single Work

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Presentations 【 Display / hide

  • Quantum op-amp and functionalities

    N. Yamamoto

    APS March Meeting (Los Angeles, California, USA) , 2018.03, Oral Presentation(general), APS

  • 散逸下における量子状態制御の限界

    小林幸一、山本直樹

    第37回量子情報技術研究会, 2017.11, Oral Presentation(general)

  • 多段量子フィードバック増幅器の感度解析

    横寺裕、山本直樹

    第36回量子情報技術研究会, 2017.05, Poster (general)

  • LQG制御による量子スクイズド状態の角度揺らぎ抑制

    黒柳亮介、山本直樹

    第35回量子情報技術シンポジウム (高エネルギー加速器研究機構) , 2016.11, Poster (general)

  • コヒーレントフィードバック制御系の設計法

    柏村慶基、山本直樹

    第35回量子情報技術シンポジウム, 2016.11, Poster (general)

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Research Projects of Competitive Funds, etc. 【 Display / hide

  • フィードバック増幅による量子機能創出

    2016.10
    -
    2020.03

    科学技術振興機構, Precursory Research for Embryonic Science and Technology, 山本直樹, Research grant, Principal Investigator

  • システム制御理論に基づく量子状態変換法の設計理論

    2015.04
    -
    2018.03

    日本学術振興会, Grant-in-Aid for Scientific Research, 山本直樹, Research grant, Principal Investigator

  • デコヒーレンスフリー量子情報処理のためのシステム制御理論

    2012.04
    -
    2015.03

    日本学術振興会, Grant-in-Aid for Scientific Research, 山本直樹, Research grant, Principal Investigator

  • 線形量子ネットワークのフィードバック制御理論

    2009.04
    -
    2012.03

    日本学術振興会, Grant-in-Aid for Scientific Research, 山本直樹, Research grant, Principal Investigator

  • 数理最適化理論に基づく大規模量子情報処理系のロバスト設計

    2008.04
    -
    2011.03

    慶応義塾大学, Keio Gijuku Academic Development Funds, 山本直樹, Research grant, Principal Investigator

Awards 【 Display / hide

  • Outstanding Reviewer Award

    2018.02, IOP

  • エレクトロニクスソサイエティ活動功労表彰

    2018.02, 電子情報通信学会

 

Courses Taught 【 Display / hide

  • GRADUATE RESEARCH ON FUNDAMENTAL SCIENCE AND TECHNOLOGY 1

    2020

  • BACHELOR'S THESIS

    2020

  • APPLIED PROBABILITY THEORY

    2020

  • GRADUATE RESEARCH ON FUNDAMENTAL SCIENCE AND TECHNOLOGY 2

    2020

  • PRESENTATION TECHNIQUE

    2020

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Courses Previously Taught 【 Display / hide

  • 応用確率論

    Keio University, 2014, Autumn Semester, Major subject, Lecture, Within own faculty, 1h

    確率・確率過程論

  • 物理情報数学A

    Keio University, 2014, Spring Semester, Major subject, Lecture, Lecturer outside of Keio, 1h

    複素関数論

 

Committee Experiences 【 Display / hide

  • 2013.04
    -
    Present

    量子情報技術時限付専門委員, 電子情報通信学会エレクトロニクスソサエティ

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    2015年 4月 ~ 2017年3月 の2年間、幹事