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Mathematical Research on Deep-Strong Coupling Regime of Interaction between Artificial Atom and Photon in Circuit QED

Research Project

Project/Area Number 20K03768
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeMulti-year Fund
Section一般
Review Section Basic Section 13010:Mathematical physics and fundamental theory of condensed matter physics-related
Research InstitutionKyushu University

Principal Investigator

Hirokawa Masao  九州大学, システム情報科学研究院, 教授 (70282788)

Project Period (FY) 2020-04-01 – 2023-03-31
Project Status Completed (Fiscal Year 2022)
Budget Amount *help
¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000)
Fiscal Year 2022: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
Fiscal Year 2021: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
Fiscal Year 2020: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
Keywords量子ラビ模型 / 深強結合領域 / シュレディンガーの猫状態 / 強結合極限 / 超対称性 / 自発的超対称性の破れ / ヒッグスポテンシャル / 質量生成 / 仮想粒子 / 実粒子 / シュレディンガーの猫風状態 / 光子 / 回路量子電磁力学 / 一般化されたラビ模型 / 2次の相互作用 / 人工原子 / 原子・光間相互作用
Outline of Research at the Start

本研究課題では,最近の回路量子電磁力学の深強結合領域における実験結果に対し,そこに介在する光子を解析し,シュレディンガーの猫的量子もつれ(SCQE)状態形成の数理物理学的構造を明らかにする.SCQE状態を形成していると思われる基底状態から光子を取り出すために,仮想光子から実光子への転化の数理構造の解明を本研究課題の核とする.この数理的研究を通し,光子を自然放射する事の無い基底状態から如何にして光子を観測するかを数理物理学的に考え,回路量子電磁力学の理論物理学,それを検証する実験物理学へと繋げることを目指す.

Outline of Final Research Achievements

I have made the mathematical research on the deep-strong coupling regime of the interaction between an artificial atom and a 1-mode photon in circuit QED. I have studied the quantum Rabi model and that model with the quadratic interaction as the mathematical models describing that physical system. I have considered the strong coupling limit for both the models, and then, I have shown that the quantum Rabi model reveals different aspects of its bound states depending on whether it has the quadratic interaction or not, which is caused by the effect coming from the virtual Bose particles. Based on the results, I have developed the mathematical theory with those models of the virtual Bose particle coupled with a qubit so that it illustrates the phase transition from supersymmetry (SUSY) to its spontaneous breaking. In particular, I have proved that the spontaneous SUSY breaking works for the mass enhancement in the fermionic states as well as the bosonic states.

Academic Significance and Societal Importance of the Research Achievements

本研究課題で,量子ビットと相互作用する仮想ボーズ粒子の数理モデルを超対称性からその自発的破れへ向かう相転移を示す数理模型へと発展させた.ボーズ粒子に関する2次の相互作用が無い場合に,清華大学の実験チームがこの数理模型による理論予想の幾つかを実験検証したと報告したが,本研究課題の結果に基づけば,そこで扱った2次の項を実験的に実現すれば,自発的超対称性の破れによる質量生成をも観ることができるかもしれない.この実験結果が報告される迄は,超対称性とその自発的破れが物理的実在なのかは未解決であったが,超対称性粒子を探す巨大施設ではなく,超対称性量子力学を実験室で検証する可能性を示唆できたように思う.

Report

(4 results)
  • 2022 Annual Research Report   Final Research Report ( PDF )
  • 2021 Research-status Report
  • 2020 Research-status Report
  • Research Products

    (5 results)

All 2023 2022 2021 2020

All Journal Article (1 results) (of which Peer Reviewed: 1 results,  Open Access: 1 results) Presentation (4 results) (of which Int'l Joint Research: 2 results,  Invited: 4 results)

  • [Journal Article] Schrodinger-cat-like states with dressed photons in renormalized adiabatic approximation for generalized quantum Rabi Hamiltonian with quadratic interaction2020

    • Author(s)
      Hirokawa Masao
    • Journal Title

      Physics Open

      Volume: 5 Pages: 100039-100039

    • DOI

      10.1016/j.physo.2020.100039

    • Related Report
      2020 Research-status Report
    • Peer Reviewed / Open Access
  • [Presentation] SUSY breaking and a radiative mass enhancement in quantum Rabi model with A^2-term2023

    • Author(s)
      M. Hirokawa
    • Organizer
      マス・フォア・イノベーション卓越大学院プログラムイベント Rabi model and Spin-Boson Model
    • Related Report
      2022 Annual Research Report
    • Int'l Joint Research / Invited
  • [Presentation] 開発の視点から見た量子コンピューティング, センシング, シミュレーション2022

    • Author(s)
      廣川真男
    • Organizer
      時間・量子測定・準古典近似の理論と実験:古典論と量子論の境界
    • Related Report
      2022 Annual Research Report
    • Invited
  • [Presentation] コンピューティング・システムとしての量子コンピュータへ向けて2022

    • Author(s)
      M. Hirokawa
    • Organizer
      量子多体計算のフロンティア
    • Related Report
      2021 Research-status Report
    • Invited
  • [Presentation] Can We Make the Noise Filtering Theory for NISQ Computer?2021

    • Author(s)
      M. Hirokawa
    • Organizer
      3rd Workshop on Quantum and Classical Cryogenic Devices, Circuits, and Systems
    • Related Report
      2021 Research-status Report
    • Int'l Joint Research / Invited

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Published: 2020-04-28   Modified: 2024-01-30  

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