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研究者情報 |
研究者業績
基本情報
研究分野
2経歴
4-
2021年4月 - 現在
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2015年4月 - 現在
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2015年12月 - 2019年3月
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2014年4月 - 2015年3月
学歴
3-
2011年4月 - 2014年3月
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2009年4月 - 2011年3月
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2005年4月 - 2009年3月
受賞
2論文
19-
Physical Review Letters, 124, 221102 (2020) 124(22) 2020年6月 査読有り最終著者責任著者
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PHYSICAL REVIEW A 101(1) 2020年1月 査読有り
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Physical Review Letters 122(071101) 2019年2月 査読有り
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International Journal of Modern Physics D (ja) 2018年 査読有り
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Progress of Theoretical and Experimental Physics 2018(1) 2018年1月1日 査読有り
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OPTICS EXPRESS 25(12) 13799-13806 2017年6月 査読有り
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PHYSICAL REVIEW A 94(3) 033822-1-033822-5 2016年9月 査読有り
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日本物理学会講演概要集 71 402-402 2016年<p>熱雑音を極限まで低減した機械光学系は巨視的量子力学の検証に用いることができ、注目を浴びている。鏡を機械的に支持すると、支持に伴うロスから熱雑音が導入されてしまうため、我々は光輻射圧のみを用いて鏡を支持する光学浮上の新手法を提案した。この光学浮上方法の安定性検証と浮上手順の確認のため、我々はねじれ振り子を使った基礎実験を行っている。本講演ではねじれ振り子実験の現状について報告する。</p>
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LIVING REVIEWS IN RELATIVITY 19(1) 2016年 査読有り
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PHYSICAL REVIEW A 92(3) 033825 2015年9月 査読有り
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OPTICS EXPRESS 22(11) 12915-12923 2014年6月 査読有り
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CPT and Lorentz Symmetry-Proceedings of the Sixth Meeting 2014年1月15日 査読有り
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PHYSICAL REVIEW D 88(11) 111101 2013年12月 査読有り
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PHYSICAL REVIEW LETTERS 110(20) 200401 2013年5月 査読有り
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CLASSICAL AND QUANTUM GRAVITY 28(9) 094011 2011年5月 査読有り
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PHYSICAL REVIEW LETTERS 106(16) 161101 2011年4月 査読有り
MISC
4-
2023年3月8日We investigated the quantum state of an optomechanical suspended mirror under continuous measurement and feedback control using Wiener filtering. We focus on the impact of the two-mode theory of suspended mirror on the quantum state, which is described by the pendulum and rotational modes. It is derived from the beam model coupled to the cavity light in the low-frequency regime, including the internal friction of the beam and the finite size effect of the mirror. We constructed a Wiener filter for the two-mode theory and predicted the quantum state by evaluating the conditional covariance matrix using Wiener filter analysis. The results demonstrate that multimode analysis may play an important role in generating the quantum squeezed state. We also point out the possibility that one-mode analysis can be a good approximation by choosing the range of the Fourier space in the Wiener filter analysis.
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2022年12月21日Pendulums have long been used as force sensors due to their ultimately low dissipation (high-quality factor) characteristic. They are widely used in the measurement of the gravitational constant, detection of gravitational waves, and determination of ultralight dark matter. Furthermore, it is expected that the quantum nature of gravity will be demonstrated by performing quantum control for macroscopic pendulums. Recently, we have demonstrated that quantum entanglement between two pendulums can be generated using an optical spring [D. Miki, N. Matsumoto, A. Matsumura, T. Shichijo, Y. Sugiyama, K. Yamamoto, and N. Yamamoto, arXiv:2210.13169 (2022)]; however, we have ignored that an optical spring can reduce the quality factor (Q-factor) by applying normal-mode splitting between the pendulum and rotational modes possessing relatively high dissipation. Herein, we analyze a system composed of a cylinder suspended using a beam (a suspended mirror, i.e., a pendulum) and an optical spring to consider normal-mode splitting. The reduction in Q-factor is determined only by the beam parameters: the ratio of the radius of the mirror to the length of the beam, and the ratio of the frequency of the rotational mode to the pendulum mode in the absence of cavity photons. In our analysis, we find that the reduction factor $4.38$ is reproduced, which is consistent with the experimental result in Matsumoto \textit{et al.} [N. Matsumoto, S. B. Catan$\tilde{\text{o } }$-Lopez, M. Sugawara, S. Suzuki, N. Abe, K. Komori, Y. Michimura, Y. Aso, and K. Edamatsu, Phys. Rev. Lett. 122, 071101 (2019)]. Our analysis shows that low dissipation (high quality) can be reached using an optical spring for the realistic pendulum system considering the rotational degree of freedom.
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2022年10月24日This study is aimed at investigating the feasibility of generating quantum entanglement between macroscopic mechanical mirrors in optomechanical systems while under continuous measurement and feedback control. We carefully derive a covariance matrix for mechanical mirrors in a steady state, employing the Kalman filtering problem with an assumed dominant cavity photon dissipation, such that the common and differential modes of the mirrors are squeezed by the action of measuring the output light beams. We demonstrate that entanglement between the mechanical mirrors is generated when the states of the common and differential modes are squeezed with high purity in an asymmetric manner. Our results also show that quantum entanglement between $7$ mg mirrors is achievable in the short term.
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2020年8月25日In quantum mechanics, measurement can be used to prepare a quantum state. This principle is applicable even for macroscopic objects, which may enable us to see classical-quantum transition. Here, we demonstrate conditional mechanical squeezing of a mg-scale suspended mirror (i.e. the center-of-mass mode of a pendulum) near quantum regimes, through continuous linear position measurement and quantum state prediction. The experiment involved the pendulum interacting with photon coherent fields in a detuned optical cavity, which creates an optical spring. Futhermore, the detuned cavity allows us to perform linear position measurement by direct photo-detection of the reflected light. We experimentally verify the conditional squeezing using the theory combining prediction and retrodiction based on the causal and anti-causal filters. As a result, the standard deviation of position and momentum are respectively given by 36 times the zero-point amplitude of position $q_{\rm zpf}$ and 89 times the zero-point amplitude of momentum $p_{\rm zpf}$. The squeezing level achieved is about 5 times closer to the zero-point motion, despite that the mass of the mechanical oscillator is approximately 7 orders of magnitude greater, compared to the previous study. Thus, our demonstration is the first step towards quantum control for massive objects whose mass-scale is high enough to measure gravitational interactions. Such quantum control will pave the way to test quantum mechanics using the center-of-mass mode of massive objects.
書籍等出版物
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Springer Japan 2016年 (ISBN: 9784431558828)https://www.springer.com/gp/book/9784431558804
講演・口頭発表等
11-
WHERE QUANTUM INFORMATION & QUANTUM TECHNOLOGIES MEET GRAVITY IN LABORATORY 2021年3月16日 招待有り
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Quantum sensors of magnetic and inertial forces 2021年3月3日 招待有り
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International Conference on Quantum Metrology and Sensing 2019年12月13日 招待有り
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Quantum Optomechanical Architectures for Dark Matter Detection 2019年10月28日 招待有り
共同研究・競争的資金等の研究課題
11-
JST 創発的研究支援事業 2021年4月 - 2028年3月
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日本学術振興会 科学研究費助成事業 2024年4月 - 2027年3月
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日本学術振興会 科学研究費助成事業 2023年4月 - 2026年3月
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日本学術振興会 卓越研究員 2021年1月 - 2024年3月
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科学研究費助成事業 基盤A 2019年4月 - 2023年3月