研究者詳細

顔写真

オザワ トモキ
小澤 知己
Tomoki Ozawa
所属
高等研究機構材料科学高等研究所 材料物理グループ
職名
教授
学位
  • Ph.D.(イリノイ大学)

  • M.S.(イリノイ大学)

経歴 9

  • 2025年4月 ~ 継続中
    東北大学 材料科学高等研究所 副所長

  • 2024年4月 ~ 継続中
    東北大学 材料科学高等研究所 教授

  • 2020年2月 ~ 2024年3月
    東北大学 材料科学高等研究所 准教授

  • 2019年10月 ~ 2022年3月
    科学技術振興機構 さきがけ研究者(兼任)

  • 2018年4月 ~ 2020年1月
    理化学研究所 数理創造プログラム 上級研究員

  • 2018年1月 ~ 2018年3月
    ブリュッセル自由大学 複雑系物理グループ 博士研究員

  • 2015年4月 ~ 2017年12月
    トレント大学 BECセンター シニア博士研究員

  • 2012年9月 ~ 2015年3月
    トレント大学 BECセンター 博士研究員

  • 2012年6月 ~ 2012年8月
    イリノイ大学アーバナ・シャンペーン校 物理学科 博士研究員

︎全件表示 ︎最初の5件までを表示

学歴 2

  • イリノイ大学アーバナ・シャンペーン校大学院 物理学科

    2006年8月 ~ 2012年5月

  • 東京大学 理学部 物理学科

    2002年4月 ~ 2006年3月

委員歴 2

  • トヨタコンポン研究所 研究アドバイザー

    2024年4月 ~ 継続中

  • アメリカ物理学会 Editorial Board Member for Physical Review A

    2023年1月 ~ 2025年12月

所属学協会 2

  • アメリカ物理学会

  • 日本物理学会

研究キーワード 5

  • トポロジカル物性

  • フォトニクス

  • 冷却原子系

  • 原子・分子・光物理学

  • 凝縮系理論

研究分野 2

  • 自然科学一般 / 半導体、光物性、原子物理 /

  • 自然科学一般 / 磁性、超伝導、強相関系 /

受賞 11

  1. 丸文研究奨励賞

    2024年3月 丸文財団

  2. 晝馬輝夫 光科学賞

    2024年3月 光科学技術研究振興財団

  3. Asian Young Scientist Fellowship

    2023年10月

  4. 東北大学ディスティングイッシュトリサーチャー

    2021年5月 東北大学

  5. 科学技術分野の文部科学大臣表彰若手科学者賞

    2021年4月 文部科学省

  6. 第15回 若手奨励賞(領域1)

    2021年3月 日本物理学会

  7. 桜舞賞(研究奨励賞)

    2020年3月 理化学研究所

  8. Outstanding Referee

    2017年 アメリカ物理学会

  9. Vijay R. Pandharipande Prize in Nuclear Physics

    2012年 イリノイ大学アーバナ・シャンペーン校

  10. Excellence in Teaching Award

    2010年 イリノイ大学アーバナ・シャンペーン校

  11. Excellence in Teaching Award

    2006年 イリノイ大学アーバナ・シャンペーン校

︎全件表示 ︎最初の5件までを表示

論文 81

  1. Geometric contribution to adiabatic amplification in non-Hermitian systems 査読有り

    Tomoki Ozawa, Henning Schomerus

    Physical Review Research 7 (1) 2025年2月18日

    出版者・発行元: American Physical Society (APS)

    DOI: 10.1103/physrevresearch.7.013173  

    eISSN:2643-1564

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    Concepts from non-Hermitian quantum mechanics have proven useful in understanding and manipulating a variety of classical systems, such as those encountered in optics, classical mechanics, and metamaterial design. Recently, the non-Hermitian analog of the Berry phase for adiabatic processes was experimentally measured. In non-Hermitian systems, the Berry phase can have an imaginary part, which contributes to the amplification or decay of the total wave intensity. When the imaginary part of the Berry curvature is zero, this geometric amplification factor is determined solely by the initial and final points of the adiabatic path in parameter space, and it does not depend on how these points are connected by the path. We list classes of non-Hermitian Hamiltonians where this path independence is guaranteed by suitable symmetries, and we find that, for some of these classes, the amplification factor can be written only in terms of the Petermann factors of the initial and final points. Our result can, in turn, be used to experimentally obtain the Petermann factor by observing how the norm of the wave function changes under adiabatic processes. We validate our theory using a couple of concrete examples of physical relevance. Published by the American Physical Society 2025

  2. Interaction-driven breakdown of Aharonov–Bohm caging in flat-band Rydberg lattices 査読有り

    Tao Chen, Chenxi Huang, Ivan Velkovsky, Tomoki Ozawa, Hannah Price, Jacob P. Covey, Bryce Gadway

    Nature Physics 21 (2) 221-227 2025年1月10日

    出版者・発行元: Springer Science and Business Media LLC

    DOI: 10.1038/s41567-024-02714-7  

    ISSN:1745-2473

    eISSN:1745-2481

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    Abstract Flat bands in condensed matter systems can host emergent states of matter, from insulating states in twisted bilayer graphene to fractionalized excitations in frustrated magnets and quantum Hall materials. A key phenomenon in certain flat-band systems is Aharonov–Bohm caging, where particles become localized due to destructive interference caused by gauge fields. Here we report on the experimental realization of highly tunable flat-band models populated by strongly interacting Rydberg atoms. By employing synthetic dimensions, we engineer a flat-band rhombic lattice with twisted boundaries and explore the control of Aharonov–Bohm caging during non-equilibrium dynamics through a tunable gauge field. Microscopic measurements of Rydberg pairs reveal the interaction-driven breakdown of Aharonov–Bohm caging in the limit of strong dipolar interactions, where lattice bands mix. In the limit of weak interactions, where caging persists, we observe effective magnetism arising from the interaction-driven mixing of degenerate flat-band states. These observations offer insights into emergent phenomena in synthetic quantum materials and expand our understanding of quantum many-body physics in engineered lattice systems.

  3. Relating the Hall conductivity to the many-body Chern number using Fermi’s Golden rule and Kramers–Kronig relations 査読有り

    Nathan Goldman, Tomoki Ozawa

    Comptes Rendus. Physique 25 (G1) 289-302 2024年9月5日

    出版者・発行元: Cellule MathDoc/Centre Mersenne

    DOI: 10.5802/crphys.191  

    eISSN:1878-1535

  4. Uniqueness of Landau levels and their analogs with higher Chern numbers 査読有り

    Bruno Mera, Tomoki Ozawa

    Physical Review Research 6 (3) 2024年9月3日

    出版者・発行元: American Physical Society (APS)

    DOI: 10.1103/physrevresearch.6.033238  

    eISSN:2643-1564

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    Landau levels are the eigenstates of a charged particle in two dimensions under a magnetic field and are at the heart of the integer and fractional quantum Hall effects, which are two prototypical phenomena showing topological features. Following recent discoveries of fractional quantum Hall phases in van der Waals materials, there is a rapid progress in understanding of the precise condition under which the fractional quantum Hall phases can be stabilized. It is now understood that the key to obtaining the fractional quantum Hall phases is the energy band whose eigenstates are holomorphic functions in both real and momentum space coordinates. Landau levels are indeed examples of such energy bands with an additional special property of having flat geometrical features. In this paper, we prove that, in fact, the only energy eigenstates having holomorphic wave functions with a flat geometry are the Landau levels and their higher Chern number analogs. Since it has been known that any holomorphic eigenstates can be constructed from the ones with a flat geometry such as the Landau levels, our uniqueness proof of the Landau levels allows one to construct any possible holomorphic eigenstate with which the fractional quantum Hall phases can be stabilized. Published by the American Physical Society 2024

  5. Bulk-entanglement spectrum correspondence in PT- and PC-symmetric topological insulators and superconductors 査読有り

    Ryo Takahashi, Tomoki Ozawa

    Physical Review Research 6 (3) 2024年8月21日

    出版者・発行元: American Physical Society (APS)

    DOI: 10.1103/physrevresearch.6.033192  

    eISSN:2643-1564

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    In this study, we discuss a type of bulk-boundary correspondence, which holds for topological insulators and superconductors when the parity-time (PT) and/or parity-particle-hole (PC) symmetry are present. In these systems, even when the bulk topology is nontrivial, the edge spectrum is generally gapped, and thus the conventional bulk-boundary correspondence does not hold. We find that, instead of the edge spectrum, the single-particle entanglement spectrum becomes gapless when the bulk topology is nontrivial: i.e., the holds in PT- and/or PC-symmetric topological insulators and superconductors. After showing the correspondence using K-theoretic approach, we provide concrete models for each symmetry class up to three dimensions where nontrivial topology because of PT and/or PC is expected. An implication of our results is that, when the bulk topology under PT and/or PC symmetry is nontrivial, the noninteracting many-body entanglement spectrum is multiply degenerate in one dimension and is gapless in two or higher dimensions. Published by the American Physical Society 2024

  6. Mean-chiral displacement in coherently driven photonic lattices and its application to synthetic frequency dimensions 査読有り

    Greta Villa, Iacopo Carusotto, Tomoki Ozawa

    Communications Physics 7 (1) 2024年7月17日

    出版者・発行元: Springer Science and Business Media LLC

    DOI: 10.1038/s42005-024-01727-1  

    eISSN:2399-3650

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    Abstract Characterizing topologically nontrivial photonic lattices by measuring their topological invariants is crucial in topological photonics. In conservative one-dimensional systems, a widely used observable to extract the winding number is the mean-chiral displacement. In many realistic photonic systems, however, losses can hardly be avoided, and little is known on how one can extend the mean-chiral displacement to a driven-dissipative context. Here we theoretically propose an experimentally viable method to directly detect the topological winding number of one-dimensional chiral photonic lattices. The method we propose is a generalization of the mean-chiral displacement to a driven-dissipative context with coherent illumination. By integrating the mean-chiral displacement of the steady state over the pump light frequency, one can obtain the winding number with a correction of the order of the loss rate squared. We demonstrate that this method can be successfully applied to lattices along synthetic frequency dimensions.

  7. Reconfigurable synthetic dimension frequency lattices in an integrated lithium niobate ring cavity 査読有り

    Hiep X. Dinh, Armandas Balčytis, Tomoki Ozawa, Yasutomo Ota, Guanghui Ren, Toshihiko Baba, Satoshi Iwamoto, Arnan Mitchell, Thach G. Nguyen

    Communications Physics 7 (1) 2024年6月11日

    出版者・発行元: Springer Science and Business Media LLC

    DOI: 10.1038/s42005-024-01676-9  

    eISSN:2399-3650

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    Abstract Harnessing non-spatial properties of photons as if they represent an additional independent coordinate underpins the emerging synthetic dimension approach. It enables probing of higher-dimensional physical models within low-dimensional devices, such as on a planar chip where this method is relatively nascent. We demonstrate an integrated thin-film lithium niobate ring resonator that, under dynamic modulation, simulates a tight-binding model with its discrete frequency modes representing lattice sites. Inter-mode coupling, and the simulated lattice geometry, can be reconfigured by controlling the modulating signals. Up to a quasi-3D lattice connectivity with controllable gauge potentials has been achieved by simultaneous synchronized nearest-, second- and third-nearest-neighbor coupling, and verified by acquiring synthetic band structures. Development of synthetic frequency dimension devices in the thin-film lithium niobate photonic integration platform is a key step in increasing the complexity of topological models achievable on a chip, combining efficient electro-optic mode coupling with non-linear effects for long-range mode interactions.

  8. Two-dimensional lattice with an imaginary magnetic field 査読有り

    Tomoki Ozawa, Tomoya Hayata

    Physical Review B 109 (8) 2024年2月8日

    出版者・発行元: American Physical Society (APS)

    DOI: 10.1103/physrevb.109.085113  

    ISSN:2469-9950

    eISSN:2469-9969

  9. Density Dependent Gauge Field Inducing Emergent Su-Schrieffer-Heeger Physics, Solitons, and Condensates in a Discrete Nonlinear Schrödinger Equation 査読有り

    W. N. Faugno, Mario Salerno, Tomoki Ozawa

    Physical Review Letters 132 (2) 2024年1月8日

    出版者・発行元: American Physical Society (APS)

    DOI: 10.1103/physrevlett.132.023401  

    ISSN:0031-9007

    eISSN:1079-7114

  10. Drude weight and the many-body quantum metric in one-dimensional Bose systems 査読有り

    G. Salerno, T. Ozawa, P. Törmä

    Physical Review B 108 (14) 2023年10月11日

    出版者・発行元: American Physical Society (APS)

    DOI: 10.1103/physrevb.108.l140503  

    ISSN:2469-9950

    eISSN:2469-9969

  11. Measuring the adiabatic non-Hermitian Berry phase in feedback-coupled oscillators 査読有り

    Yaashnaa Singhal, Enrico Martello, Shraddha Agrawal, Tomoki Ozawa, Hannah Price, Bryce Gadway

    Physical Review Research 5 (3) 2023年8月24日

    出版者・発行元: American Physical Society (APS)

    DOI: 10.1103/physrevresearch.5.l032026  

    eISSN:2643-1564

  12. Bulk-edge correspondence of Stiefel-Whitney and Euler insulators through the entanglement spectrum and cutting procedure 査読有り

    Ryo Takahashi, Tomoki Ozawa

    Physical Review B 108 (7) 2023年8月11日

    出版者・発行元: American Physical Society (APS)

    DOI: 10.1103/physrevb.108.075129  

    ISSN:2469-9950

    eISSN:2469-9969

  13. Edge-to-edge topological spectral transfer in diamond photonic lattices 査読有り

    Gabriel Cáceres-Aravena, Bastián Real, Diego Guzmán-Silva, Paloma Vildoso, Ignacio Salinas, Alberto Amo, Tomoki Ozawa, Rodrigo A. Vicencio

    APL Photonics 8 (8) 2023年8月1日

    出版者・発行元: AIP Publishing

    DOI: 10.1063/5.0153770  

    eISSN:2378-0967

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    The transfer of information between topological edge states is a robust way of spatially manipulating spatial states in lattice environments. This method is particularly efficient when the edge modes are kept within the topological gap of the lattice during the transfer. In this work, we show experimentally the transfer of photonic modes between topological edge states located at opposite ends of a dimerized one-dimensional photonic lattice. We use a diamond lattice of coupled waveguides and show that the topological transfer is insensitive to the presence of a high density of states in the form of a flat band at an energy close to that of the edge states and prevails in the presence of a hopping impurity. We explore the dynamics in the waveguide lattice using a wavelength-scan method, where different input wavelengths translate into different effective lattice lengths. Our results offer an alternative way to the implementation of efficient transfer protocols based on active driving mechanisms.

  14. Synthetic mechanical lattices with synthetic interactions 査読有り

    Ritika Anandwade, Yaashnaa Singhal, Sai Naga Manoj Paladugu, Enrico Martello, Michael Castle, Shraddha Agrawal, Ellen Carlson, Cait Battle-McDonald, Tomoki Ozawa, Hannah M. Price, Bryce Gadway

    Physical Review A 108 (1) 2023年7月28日

    出版者・発行元: American Physical Society (APS)

    DOI: 10.1103/physreva.108.012221  

    ISSN:2469-9926

    eISSN:2469-9934

  15. Coexistence of stable and unstable population dynamics in a nonlinear non-Hermitian mechanical dimer 査読有り

    Enrico Martello, Yaashnaa Singhal, Bryce Gadway, Tomoki Ozawa, Hannah M. Price

    Physical Review E 107 (6) 2023年6月26日

    出版者・発行元: American Physical Society (APS)

    DOI: 10.1103/physreve.107.064211  

    ISSN:2470-0045

    eISSN:2470-0053

  16. 人工量子系の物性物理とトポロジカル物性 招待有り

    小澤知己

    第67回物性若手夏の学校 講義ノート 188 2023年2月

  17. Singular-connection approach to topological phases and resonant optical responses 査読有り

    Bruno Mera, Tomoki Ozawa

    Physical Review B 106 (24) 2022年12月20日

    出版者・発行元: American Physical Society (APS)

    DOI: 10.1103/physrevb.106.245134  

    ISSN:2469-9950

    eISSN:2469-9969

  18. Quantum Fisher information measurement and verification of the quantum Cramér–Rao bound in a solid-state qubit 査読有り

    Min Yu, Yu Liu, Pengcheng Yang, Musang Gong, Qingyun Cao, Shaoliang Zhang, Haibin Liu, Markus Heyl, Tomoki Ozawa, Nathan Goldman, Jianming Cai

    npj Quantum Information 8 (1) 2022年12月

    出版者・発行元: Springer Science and Business Media LLC

    DOI: 10.1038/s41534-022-00547-x  

    eISSN:2056-6387

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    Abstract The quantum Cramér–Rao bound sets a fundamental limit on the accuracy of unbiased parameter estimation in quantum systems, relating the uncertainty in determining a parameter to the inverse of the quantum Fisher information. We experimentally demonstrate near saturation of the quantum Cramér–Rao bound in the phase estimation of a solid-state spin system, provided by a nitrogen-vacancy center in diamond. This is achieved by comparing the experimental uncertainty in phase estimation with an independent measurement of the related quantum Fisher information. The latter is independently extracted from coherent dynamical responses of the system under weak parametric modulations, without performing any quantum-state tomography. While optimal parameter estimation has already been observed for quantum devices involving a limited number of degrees of freedom, our method offers a versatile and powerful experimental tool to explore the Cramér–Rao bound and the quantum Fisher information in systems of higher complexity, as relevant for quantum technologies.

  19. Interaction-Induced Non-Hermitian Topological Phases from a Dynamical Gauge Field 査読有り

    W. N. Faugno, Tomoki Ozawa

    Physical Review Letters 129 (18) 2022年10月24日

    出版者・発行元: American Physical Society (APS)

    DOI: 10.1103/physrevlett.129.180401  

    ISSN:0031-9007

    eISSN:1079-7114

  20. Roadmap on topological photonics 査読有り

    Hannah Price, Yidong Chong, Alexander Khanikaev, Henning Schomerus, Lukas J Maczewsky, Mark Kremer, Matthias Heinrich, Alexander Szameit, Oded Zilberberg, Yihao Yang, Baile Zhang, Andrea Alù, Ronny Thomale, Iacopo Carusotto, Philippe St-Jean, Alberto Amo, Avik Dutt, Luqi Yuan, Shanhui Fan, Xuefan Yin, Chao Peng, Tomoki Ozawa, Andrea Blanco-Redondo

    Journal of Physics: Photonics 4 (3) 032501-032501 2022年7月1日

    出版者・発行元: IOP Publishing

    DOI: 10.1088/2515-7647/ac4ee4  

    eISSN:2515-7647

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    Abstract Topological photonics seeks to control the behaviour of the light through the design of protected topological modes in photonic structures. While this approach originated from studying the behaviour of electrons in solid-state materials, it has since blossomed into a field that is at the very forefront of the search for new topological types of matter. This can have real implications for future technologies by harnessing the robustness of topological photonics for applications in photonics devices. This roadmap surveys some of the main emerging areas of research within topological photonics, with a special attention to questions in fundamental science, which photonics is in an ideal position to address. Each section provides an overview of the current and future challenges within a part of the field, highlighting the most exciting opportunities for future research and developments.

  21. Band structures under non-Hermitian periodic potentials: Connecting nearly-free and bi-orthogonal tight-binding models 査読有り

    Ken Mochizuki, Tomoki Ozawa

    Physical Review B 105 (17) 2022年5月19日

    出版者・発行元: American Physical Society (APS)

    DOI: 10.1103/physrevb.105.174108  

    ISSN:2469-9950

    eISSN:2469-9969

  22. Synthetic dimension band structures on a Si CMOS photonic platform 査読有り

    Armandas Balčytis, Tomoki Ozawa, Yasutomo Ota, Satoshi Iwamoto, Jun Maeda, Toshihiko Baba

    Science Advances 8 (4) 2022年1月28日

    出版者・発行元: American Association for the Advancement of Science (AAAS)

    DOI: 10.1126/sciadv.abk0468  

    eISSN:2375-2548

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    Synthetic dimensions, which simulate spatial coordinates using nonspatial degrees of freedom, are drawing interest in topological science and other fields for modeling higher-dimensional phenomena on simple structures. We present the first realization of a synthetic frequency dimension on a silicon ring resonator integrated photonic device fabricated using a CMOS process. We confirm that its coupled modes correspond to a one-dimensional tight-binding model through acquisition of up to 280-GHz bandwidth optical frequency comb-like spectra and by measuring synthetic band structures. Furthermore, we realized two types of gauge potentials along the frequency dimension and probed their effects through the associated band structures. An electric field analog was produced via modulation detuning, whereas effective magnetic fields were induced using synchronized nearest- and second nearest–neighbor couplings. Creation of coupled mode lattices and two effective forces on a monolithic Si CMOS device represents a key step toward wider adoption of topological principles.

  23. Author Correction: Lasing in topological edge states of a one-dimensional lattice

    P. St-Jean, V. Goblot, E. Galopin, A. Lemaître, T. Ozawa, L. Le Gratiet, I. Sagnes, J. Bloch, A. Amo

    Nature Photonics 15 (11) 862-862 2021年7月7日

    出版者・発行元: Springer Science and Business Media LLC

    DOI: 10.1038/s41566-021-00846-3  

    ISSN:1749-4885

    eISSN:1749-4893

  24. Photonic Topological Materials: feature introduction 招待有り

    Tomoki Ozawa, Ramy El-Ganainy, Alberto Amo

    Optical Materials Express 11 (6) 1592-1592 2021年6月1日

    出版者・発行元: The Optical Society

    DOI: 10.1364/ome.430428  

    ISSN:2159-3930

    eISSN:2159-3930

  25. Spatial and spectral mode-selection effects in topological lasers with frequency-dependent gain 査読有り

    Secl{\`i}, M., Ozawa, T., Capone, M., Carusotto, I.

    APL Photonics 6 (5) 050803-050803 2021年5月1日

    出版者・発行元: AIP Publishing

    DOI: 10.1063/5.0041124  

    ISSN:2378-0967

    eISSN:2378-0967

  26. Artificial magnetic field for synthetic quantum matter without dynamical modulation 査読有り

    Ozawa, T.

    Physical Review A 103 (3) 2021年3月19日

    出版者・発行元: American Physical Society (APS)

    DOI: 10.1103/PhysRevA.103.033318  

    ISSN:2469-9934 2469-9926

    eISSN:2469-9934

  27. Relations between topology and the quantum metric for Chern insulators 査読有り

    Ozawa, T., Mera, B.

    Physical Review B 104 (4) 2021年

    DOI: 10.1103/PhysRevB.104.045103  

    ISSN:2469-9969 2469-9950

  28. Engineering geometrically flat Chern bands with Fubini-Study Kähler structure 査読有り

    Mera, B., Ozawa, T.

    Physical Review B 104 (11) 2021年

    DOI: 10.1103/PhysRevB.104.115160  

    ISSN:2469-9969 2469-9950

  29. Kähler geometry and Chern insulators: Relations between topology and the quantum metric KÄHLER GEOMETRY and CHERN INSULATORS: ... BRUNO MERA and TOMOKI OZAWA 査読有り

    Mera, B., Ozawa, T.

    Physical Review B 104 (4) 2021年

    DOI: 10.1103/PhysRevB.104.045104  

    ISSN:2469-9969 2469-9950

  30. Erratum: Photonic topological materials feature issue (Optical Materials Express (2021) 11:4 (1119) DOI: 10.1364/OME.427194)

    Amo, A., Ozawa, T., El-Ganainy, R.

    Optical Materials Express 11 (5) 1410-1410 2021年

    DOI: 10.1364/OME.11.001410  

    ISSN:2159-3930

  31. Direct observation of photonic Landau levels and helical edge states in strained honeycomb lattices 査読有り

    Jamadi, O., Rozas, E., Salerno, G., Mili?evi?, M., Ozawa, T., Sagnes, I., Lema{\^i}tre, A., Le Gratiet, L., Harouri, A., Carusotto, I., Bloch, J., Amo, A.

    Light: Science and Applications 9 (1) 2020年12月

    出版者・発行元: Springer Science and Business Media LLC

    DOI: 10.1038/s41377-020-00377-6  

    ISSN:2047-7538 2095-5545

    eISSN:2047-7538

  32. Semi-Dirac Transport and Anisotropic Localization in Polariton Honeycomb Lattices 査読有り

    Real, B., Jamadi, O., Mili?evi?, M., Pernet, N., St-Jean, P., Ozawa, T., Montambaux, G., Sagnes, I., Lema{\^i}tre, A., Le Gratiet, L., Harouri, A., Ravets, S., Bloch, J., Amo, A.

    Physical Review Letters 125 (18) 2020年10月28日

    出版者・発行元: American Physical Society (APS)

    DOI: 10.1103/PhysRevLett.125.186601  

    ISSN:1079-7114 0031-9007

    eISSN:1079-7114

  33. Synthetic dimensions and topological chiral currents in mesoscopic rings 査読有り

    Price, H.M., Ozawa, T., Schomerus, H.

    Physical Review Research 2 (3) 2020年7月16日

    出版者・発行元: American Physical Society (APS)

    DOI: 10.1103/PhysRevResearch.2.032017  

    ISSN:2643-1564

    eISSN:2643-1564

  34. 人工次元を用いたトポロジカル物性の研究 招待有り 査読有り

    小澤知己

    日本物理学会誌 75 (4) 201 2020年4月

  35. Experimental measurement of the quantum geometric tensor using coupled qubits in diamond 査読有り

    Yu, M., Yang, P., Gong, M., Cao, Q., Lu, Q., Liu, H., Zhang, S., Plenio, M.B., Jelezko, F., Ozawa, T., Goldman, N., Cai, J.

    National Science Review 7 (2) 254-260 2020年2月1日

    出版者・発行元: Oxford University Press (OUP)

    DOI: 10.1093/nsr/nwz193  

    ISSN:2053-714X 2095-5138

    eISSN:2053-714X

  36. Active topological photonics 査読有り

    Yasutomo Ota, Kenta Takata, Tomoki Ozawa, Alberto Amo, Zhetao Jia, Boubacar Kante, Masaya Notomi, Yasuhiko Arakawa, Satoshi Iwamoto

    Nanophotonics 9 (3) 547-567 2020年1月28日

    出版者・発行元: Walter de Gruyter GmbH

    DOI: 10.1515/nanoph-2019-0376  

    ISSN:2192-8614

    eISSN:2192-8614

  37. Probing localization and quantum geometry by spectroscopy 査読有り

    Ozawa, T., Goldman, N.

    Physical Review Research 1 (3) 032019(R) 2019年11月

    DOI: 10.1103/PhysRevResearch.1.032019  

    ISSN:2643-1564

  38. Exploring topological photonics in synthetic dimensions

    Hannah M. Price, Tomoki Ozawa, Nathan Goldman, Oded Zilberberg, Iacopo Carusotto

    2019 Conference on Lasers and Electro-Optics Europe and European Quantum Electronics Conference, CLEO/Europe-EQEC 2019 2019年6月1日

    出版者・発行元: Institute of Electrical and Electronics Engineers Inc.

    DOI: 10.1109/CLEOE-EQEC.2019.8872904  

  39. Topological and geometrical effects in the bulk hall response of driven-dissipative photonic lattices

    Tomoki Ozawa, Iacopo Carusotto

    2019 Conference on Lasers and Electro-Optics Europe and European Quantum Electronics Conference, CLEO/Europe-EQEC 2019 2019年6月1日

    出版者・発行元: Institute of Electrical and Electronics Engineers Inc.

    DOI: 10.1109/CLEOE-EQEC.2019.8873225  

  40. Type-III and Tilted Dirac Cones Emerging from Flat Bands in Photonic Orbital Graphene 査読有り

    Mili?evi?, M., Montambaux, G., Ozawa, T., Jamadi, O., Real, B., Sagnes, I., Lema{\^i}tre, A., Le Gratiet, L., Harouri, A., Bloch, J., Amo, A.

    Physical Review X 9 (3) 031010 2019年

    DOI: 10.1103/PhysRevX.9.031010  

    ISSN:2160-3308

  41. Topological quantum matter in synthetic dimensions 招待有り 査読有り

    Ozawa, T., Price, H.M.

    Nature Reviews Physics 1 (5) 349-357 2019年

    DOI: 10.1038/s42254-019-0045-3  

    ISSN:2522-5820

  42. Measuring quantized circular dichroism in ultracold topological matter 査読有り

    Asteria, L., Tran, D.T., Ozawa, T., Tarnowski, M., Rem, B.S., Fl{\"a}schner, N., Sengstock, K., Goldman, N., Weitenberg, C.

    Nature Physics 15 (5) 449-454 2019年

    DOI: 10.1038/s41567-019-0417-8  

    ISSN:1745-2481 1745-2473

  43. Topological photonics 招待有り 査読有り

    Ozawa, T., Price, H.M., Amo, A., Goldman, N., Hafezi, M., Lu, L., Rechtsman, M.C., Schuster, D., Simon, J., Zilberberg, O., Carusotto, I.

    Reviews of Modern Physics 91 (1) 015006 2019年

    DOI: 10.1103/RevModPhys.91.015006  

    ISSN:1539-0756 0034-6861

  44. Steady-state Hall response and quantum geometry of driven-dissipative lattices 査読有り

    Ozawa, T.

    Physical Review B 97 (4) 041108(R) 2018年

    DOI: 10.1103/PhysRevB.97.041108  

    ISSN:2469-9969 2469-9950

  45. Extracting the quantum metric tensor through periodic driving 査読有り

    Ozawa, T., Goldman, N.

    Physical Review B 97 (20) 201117(R) 2018年

    DOI: 10.1103/PhysRevB.97.201117  

    ISSN:2469-9969 2469-9950

  46. Lasing in topological edge states of a one-dimensional lattice 査読有り

    P. St-Jean, V. Goblot, E. Galopin, A. Lemaitre, T. Ozawa, L. Le Gratiet, I. Sagnes, J. Bloch, A. Amo

    NATURE PHOTONICS 11 (10) 651-+ 2017年10月

    DOI: 10.1038/s41566-017-0006-2  

    ISSN:1749-4885

    eISSN:1749-4893

  47. Klein tunneling in driven-dissipative photonic graphene 査読有り

    Tomoki Ozawa, Alberto Amo, Jacqueline Bloch, Iacopo Carusotto

    PHYSICAL REVIEW A 96 (1) 2017年7月

    DOI: 10.1103/PhysRevA.96.013813  

    ISSN:2469-9926

    eISSN:2469-9934

  48. Propagating edge states in strained honeycomb lattices 査読有り

    Grazia Salerno, Tomoki Ozawa, Hannah M. Price, Iacopo Carusotto

    PHYSICAL REVIEW B 95 (24) 2017年6月

    DOI: 10.1103/PhysRevB.95.245418  

    ISSN:2469-9950

    eISSN:2469-9969

  49. Spin-orbit coupling in a hexagonal ring of pendula 査読有り

    Grazia Salerno, Alice Berardo, Tomoki Ozawa, Hannah M. Price, Ludovic Taxis, Nicola M. Pugno, Iacopo Carusotto

    NEW JOURNAL OF PHYSICS 19 (5) 2017年5月

    DOI: 10.1088/1367-2630/aa6c03  

    ISSN:1367-2630

  50. Orbital Edge States in a Photonic Honeycomb Lattice 査読有り

    M. Milicevic, T. Ozawa, G. Montambaux, I. Carusotto, E. Galopin, A. Lemaitre, L. Le Gratiet, I. Sagnes, J. Bloch, A. Amo

    PHYSICAL REVIEW LETTERS 118 (10) 2017年3月

    DOI: 10.1103/PhysRevLett.118.107403  

    ISSN:0031-9007

    eISSN:1079-7114

  51. Synthetic dimensions for cold atoms from shaking a harmonic trap 査読有り

    Hannah M. Price, Tomoki Ozawa, Nathan Goldman

    PHYSICAL REVIEW A 95 (2) 2017年2月

    DOI: 10.1103/PhysRevA.95.023607  

    ISSN:2469-9926

    eISSN:2469-9934

  52. Synthetic Dimensions with Magnetic Fields and Local Interactions in Photonic Lattices 査読有り

    Tomoki Ozawa, Iacopo Carusotto

    PHYSICAL REVIEW LETTERS 118 (1) 2017年1月

    DOI: 10.1103/PhysRevLett.118.013601  

    ISSN:0031-9007

    eISSN:1079-7114

  53. Optical-lattice-assisted magnetic phase transition in a spin-orbit-coupled Bose-Einstein condensate 査読有り

    Giovanni I. Martone, Tomoki Ozawa, Chunlei Qu, Sandro Stringari

    PHYSICAL REVIEW A 94 (4) 2016年10月

    DOI: 10.1103/PhysRevA.94.043629  

    ISSN:2469-9926

    eISSN:2469-9934

  54. Measurement of Chern numbers through center-of-mass responses 査読有り

    H. M. Price, O. Zilberberg, T. Ozawa, I. Carusotto, N. Goldman

    PHYSICAL REVIEW B 93 (24) 2016年6月

    DOI: 10.1103/PhysRevB.93.245113  

    ISSN:2469-9950

    eISSN:2469-9969

  55. Quantum Hall effect in momentum space 査読有り

    Tomoki Ozawa, Hannah M. Price, Iacopo Carusotto

    PHYSICAL REVIEW B 93 (19) 2016年5月

    DOI: 10.1103/PhysRevB.93.195201  

    ISSN:2469-9950

    eISSN:2469-9969

  56. Synthetic dimensions in integrated photonics: From optical isolation to four-dimensional quantum Hall physics 査読有り

    Tomoki Ozawa, Hannah M. Price, Nathan Goldman, Oded Zilberberg, Iacopo Carusotto

    PHYSICAL REVIEW A 93 (4) 2016年4月

    DOI: 10.1103/PhysRevA.93.043827  

    ISSN:2469-9926

    eISSN:2469-9934

  57. Floquet topological system based on frequency-modulated classical coupled harmonic oscillators 査読有り

    Grazia Salerno, Tomoki Ozawa, Hannah M. Price, Iacopo Carusotto

    PHYSICAL REVIEW B 93 (8) 2016年2月

    DOI: 10.1103/PhysRevB.93.085105  

    ISSN:2469-9950

    eISSN:2469-9969

  58. Momentum-space Landau levels in driven-dissipative cavity arrays 査読有り

    Andrei C. Berceanu, Hannah M. Price, Tomoki Ozawa, Iacopo Carusotto

    PHYSICAL REVIEW A 93 (1) 2016年1月

    DOI: 10.1103/PhysRevA.93.013827  

    ISSN:1050-2947

    eISSN:1094-1622

  59. Momentum-space Landau levels in arrays of coupled ring resonators 査読有り

    Hannah M. Price, Andrei C. Berceanu, Tomoki Ozawa, Iacopo Carusotto

    ADVANCES IN PHOTONICS OF QUANTUM COMPUTING, MEMORY, AND COMMUNICATION IX 9762 2016年

    DOI: 10.1117/12.2218615  

    ISSN:0277-786X

  60. Towards four-dimensional photonics 査読有り

    Hannah M. Price, Tomoki Ozawa, Nathan Goldman, Oded Zilberberg, Iacopo Carusotto

    ADVANCES IN PHOTONICS OF QUANTUM COMPUTING, MEMORY, AND COMMUNICATION IX 9762 2016年

    DOI: 10.1117/12.2218539  

    ISSN:0277-786X

  61. Four-Dimensional Quantum Hall Effect with Ultracold Atoms 査読有り

    H. M. Price, O. Zilberberg, T. Ozawa, I. Carusotto, N. Goldman

    PHYSICAL REVIEW LETTERS 115 (19) 2015年11月

    DOI: 10.1103/PhysRevLett.115.195303  

    ISSN:0031-9007

    eISSN:1079-7114

  62. ULTRACOLD ATOMS Feel the gauge 査読有り

    Tomoki Ozawa

    NATURE PHYSICS 11 (10) 801-802 2015年10月

    DOI: 10.1038/nphys3447  

    ISSN:1745-2473

    eISSN:1745-2481

  63. Edge states in polariton honeycomb lattices 査読有り

    M. Milicevic, T. Ozawa, P. Andreakou, I. Carusotto, T. Jacqmin, E. Galopin, A. Lemaitre, L. Le Gratiet, I. Sagnes, J. Bloch, A. Amo

    2D MATERIALS 2 (3) 2015年9月

    DOI: 10.1088/2053-1583/2/3/034012  

    ISSN:2053-1583

  64. How to directly observe Landau levels in driven-dissipative strained honeycomb lattices 査読有り

    Grazia Salerno, Tomoki Ozawa, Hannah M. Price, Iacopo Carusotto

    2D MATERIALS 2 (3) 2015年9月

    DOI: 10.1088/2053-1583/2/3/034015  

    ISSN:2053-1583

  65. Momentum-space Harper-Hofstadter model 査読有り

    Tomoki Ozawa, Hannah M. Price, Iacopo Carusotto

    PHYSICAL REVIEW A 92 (2) 2015年8月

    DOI: 10.1103/PhysRevA.92.023609  

    ISSN:1050-2947

    eISSN:1094-1622

  66. Artificial magnetic fields in momentum space in spin-orbit-coupled systems 査読有り

    Hannah M. Price, Tomoki Ozawa, Nigel R. Cooper, Iacopo Carusotto

    PHYSICAL REVIEW A 91 (3) 2015年3月

    DOI: 10.1103/PhysRevA.91.033606  

    ISSN:1050-2947

    eISSN:1094-1622

  67. Quantum Mechanics with a Momentum-Space Artificial Magnetic Field 査読有り

    Hannah M. Price, Tomoki Ozawa, Iacopo Carusotto

    PHYSICAL REVIEW LETTERS 113 (19) 2014年11月

    DOI: 10.1103/PhysRevLett.113.190403  

    ISSN:0031-9007

    eISSN:1079-7114

  68. Chandrasekhar-Clogston limit and critical polarization in a Fermi-Bose superfluid mixture 査読有り

    Tomoki Ozawa, Alessio Recati, Marion Delehaye, Frederic Chevy, Sandro Stringari

    PHYSICAL REVIEW A 90 (4) 2014年10月

    DOI: 10.1103/PhysRevA.90.043608  

    ISSN:2469-9926

    eISSN:2469-9934

  69. Anomalous and Quantum Hall Effects in Lossy Photonic Lattices 査読有り

    Tomoki Ozawa, Iacopo Carusotto

    PHYSICAL REVIEW LETTERS 112 (13) 2014年4月

    DOI: 10.1103/PhysRevLett.112.133902  

    ISSN:0031-9007

    eISSN:1079-7114

  70. Condensation of bosons with Rashba-Dresselhaus spin-orbit coupling 査読有り

    Gordon Baym, Tomoki Ozawa

    17TH INTERNATIONAL CONFERENCE ON RECENT PROGRESS IN MANY-BODY THEORIES (MBT17) 529 2014年

    DOI: 10.1088/1742-6596/529/1/012006  

    ISSN:1742-6588

  71. Discontinuities in the First and Second Sound Velocities at the Berezinskii-Kosterlitz-Thouless Transition 査読有り

    Tomoki Ozawa, Sandro Stringari

    PHYSICAL REVIEW LETTERS 112 (2) 2014年1月

    DOI: 10.1103/PhysRevLett.112.025302  

    ISSN:0031-9007

    eISSN:1079-7114

  72. Supercurrent and dynamical instability of spin-orbit-coupled ultracold Bose gases 査読有り

    Ozawa, T., Pitaevskii, L.P., Stringari, S.

    Physical Review A - Atomic, Molecular, and Optical Physics 87 (6) 2013年6月

    DOI: 10.1103/PhysRevA.87.063610  

    ISSN:1050-2947 1094-1622

  73. Condensation transition of ultracold bose gases with rashba spin-orbit coupling 査読有り

    Ozawa, T., Baym, G.

    Physical Review Letters 110 (8) 2013年2月

    DOI: 10.1103/PhysRevLett.110.085304  

    ISSN:0031-9007 1079-7114

  74. Erratum: Striped states in weakly trapped ultracold Bose gases with Rashba spin-orbit coupling [Phys. Rev. A85, 063623 (2012)]

    Tomoki Ozawa, Gordon Baym

    Physical Review A 86 (1) 2012年7月26日

    DOI: 10.1103/physreva.86.019905  

    ISSN:1050-2947

    eISSN:1094-1622

  75. Stability of Ultracold Atomic Bose Condensates with Rashba Spin-Orbit Coupling against Quantum and Thermal Fluctuations 査読有り

    Tomoki Ozawa, Gordon Baym

    PHYSICAL REVIEW LETTERS 109 (2) 2012年7月

    DOI: 10.1103/PhysRevLett.109.025301  

    ISSN:0031-9007

  76. Striped states in weakly trapped ultracold Bose gases with Rashba spin-orbit coupling 査読有り

    Tomoki Ozawa, Gordon Baym

    PHYSICAL REVIEW A 85 (6) 2012年6月

    DOI: 10.1103/PhysRevA.85.063623  

    ISSN:1050-2947

  77. Ground-state phases of ultracold bosons with Rashba-Dresselhaus spin-orbit coupling 査読有り

    Tomoki Ozawa, Gordon Baym

    PHYSICAL REVIEW A 85 (1) 2012年1月

    DOI: 10.1103/PhysRevA.85.013612  

    ISSN:1050-2947

  78. Renormalization of interactions of ultracold atoms in simulated Rashba gauge fields 査読有り

    Tomoki Ozawa, Gordon Baym

    PHYSICAL REVIEW A 84 (4) 2011年10月

    DOI: 10.1103/PhysRevA.84.043622  

    ISSN:1050-2947

  79. Plastid-to-nucleus retrograde signals are essential for the expression of nuclear starch biosynthesis genes during amyloplast differentiation in tobacco BY-2 cultured cells

    Enami, K., Ozawa, T., Motohashi, N., Nakamura, M., Tanaka, K., Hanaoka, M.

    Plant Physiology 157 (1) 2011年

    DOI: 10.1104/pp.111.178897  

    ISSN:1532-2548 0032-0889

  80. Population imbalance and pairing in the BCS-BEC crossover of three-component ultracold fermions 査読有り

    Tomoki Ozawa, Gordon Baym

    PHYSICAL REVIEW A 82 (6) 2010年12月

    DOI: 10.1103/PhysRevA.82.063615  

    ISSN:1050-2947

  81. Two-slit diffraction with highly charged particles: Niels Bohr's consistency argument that the electromagnetic field must be quantized 査読有り

    Gordon Baym, Tomoki Ozawa

    PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA 106 (9) 3035-3040 2009年3月

    DOI: 10.1073/pnas.0813239106  

    ISSN:0027-8424

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書籍等出版物 2

  1. Quantum Fluids of Light and Matter, Proceedings of the International School of Physics "Enrico Fermi"

    Alberto Bramati, Iacopo Carusotto, Cristiano Ciuti

    IOS Press 2025年

    ISBN: 9781643685748

  2. 研究者、生活を語る : 「両立」の舞台裏

    岩波書店編集部

    岩波書店 2024年10月

    ISBN: 9784000616614

共同研究・競争的資金等の研究課題 7

  1. 非エルミート量子系における幾何学的効果の研究

    小澤 知己

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research

    研究種目:Grant-in-Aid for Scientific Research (B)

    研究機関:Tohoku University

    2024年4月 ~ 2028年3月

  2. 量子幾何とトポロジーを用いたAMO量子技術の開発

    小澤知己

    2023年10月 ~ 2027年3月

  3. 自己駆動する集団におけるカイラル輸送現象の研究

    早田 智也, 川口 喬吾, 小澤 知己

    2021年4月 ~ 2024年3月

  4. 量子計量・量子幾何テンソルを用いた局在とトポロジーの研究

    小澤 知己

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

    研究種目:Grant-in-Aid for Scientific Research (B)

    研究機関:Institute of Physical and Chemical Research

    2020年4月 ~ 2024年3月

    詳細を見る 詳細を閉じる

    量子計量とトポロジーの関係という観点からは、量子計量を使って測った運動量空間の体積とトポロジカルなチャーン数との不等式の関係を導き、この不等式が等式となる条件がBloch波動関数が正則関数になるという条件と同値であることを導いた。具体的な模型を通じてこの関係を確かめ、2バンド系では等式が厳密に成り立つことが多いこと、また、多バンド系では模型がランダウ準位に近づくに従い等式に近づいていくということも確認した。この方法を用いれば量子計量というリーマン幾何学的な情報をもとにチャーン数というトポロジカルな性質に関しての情報を得ることができる。 また、この関係を用いて量子計量とトポロジーの間に等式が成り立つようなチャーン絶縁体で、かつ、量子計量やベリー曲率が運動量空間上で一様になるような模型を運動量空間(トーラス)上の正則関数(テータ関数)を用いて具体的に漸近的に構成する方法も提示できた。この構成法で得られる模型は量子計量・ベリー曲率が一様に近いが完全に一様ではない。実は完全に一様になる模型は有限バンドの模型では構成不可能であり、そのことを証明することもできた。 少なくとも一粒子系に関しては量子計量とトポロジーの関係はこれらの研究によりかなり明らかになったと言って良い。多粒子系への拡張の第一歩として自由電子系での多体の量子計量とチャーン数の間の不等式も導いている。多体の量子計量はひねり境界条件の空間で定義されており、相互作用系への自然な拡張も期待できる。

  5. 原子・分子・光物理学におけるトポロジカル物性とその応用

    小澤知己

    提供機関:JST

    制度名:PRESTO

    2019年10月 ~ 2023年3月

  6. 冷却原子系における高次元物理現象の理論研究 競争的資金

    小澤 知己

    提供機関:Japan Society for the Promotion of Science

    制度名:KAKENHI Research Activity Start-up

    2018年8月 ~ 2020年3月

  7. Novel method for realizing artificial magnetic fields in ultracold atomic gases 競争的資金

    小澤 知己

    提供機関:RIKEN

    制度名:Incentive Research Projects

    2018年 ~ 2019年

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担当経験のある科目(授業) 6

  1. (集中講義)人工量子物質における量子シミュレーションとトポロジカル物性 東京工業大学

  2. An Introduction to Topological Phases of Matter トレント大学

  3. Statistical Physics イリノイ大学アーバナ・シャンペーン校

  4. Quantum Mechanics I イリノイ大学アーバナ・シャンペーン校

  5. College Physics: Mechanics & Heat イリノイ大学アーバナ・シャンペーン校

  6. University Physics: Thermal & Quantum Physics イリノイ大学アーバナ・シャンペーン校

︎全件表示 ︎最初の5件までを表示