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初貝 安弘 ORCID iD icon
物理学専攻 教授
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ResercherID: Y.Hatsugai
吉田 恒也
平成17年4月: 大阪市立大学 理学部 物質科学科 入学
平成21年4月: 京都大学大学院理学研究科 物理学・宇宙物理専攻 物理学第一分野修士課程 入学
平成23年4月: 京都大学大学院理学研究科 物理学・宇宙物理専攻 物理学第一分野博士後期課程 進学
平成26年3月: 博士号:京都大学、博士(理学) 取得 (指導教員:川上則雄 教授)
平成 24年 4月 学振特別研究員(DC2)
平成 26年 4月 理化学研究所 基礎科学特別研究員 (古崎物性理論研究室)
平成 28年 4月 京都大学大学院 物理学・宇宙物理学専攻 特定研究員 (凝縮系理論グループ)
平成 30年 4月 筑波大学 数理物質系 助教 (初貝研究室)

今年もやります。まずは量子力学3(遠隔). 冬は 統計力学2 改め物性理論4 (大学院「ベリー接続の理論とバルクエッジ対応」). 令和二年の新年あけましておめでとうございます。今年もあと148日!
投稿者 : hatsugai 投稿日時: 2020-07-30 12:47:16 (33 ヒット)

Our article on non-hermitian band touching for strongly correlated systems has been published in PTEP (Progress of Theoretical and Experimental Physics), "Exceptional band touching for strongly correlated systems in equilibrium", by Tsuneya Yoshida, Robert Peters, Norio Kawakami, Yasuhiro Hatsugai. Focusing on the non-hermitian topological phenomena for the equilibrium Green function of correlated electrons, a compact review of the exceptonal band touching that is intrinsic for non-hermitian matrices is described as well. Have a look at.

投稿者 : hatsugai 投稿日時: 2020-07-09 12:45:13 (105 ヒット)

Mass points on a periodic lattice connected by springs (spring-mass model) is a simple mechanical system described by an energy-momentum dispersion, that is a macroscopic phonon. We hereby discuss it on the Lieb lattice with chiral symmetry. It possesses extra degeneracy at some momentum compared with well investigated electronic systems (due to extra degree of freedoms). Have a look at "Topological Modes Protected by Chiral and Two-Fold Rotational Symmetry in a Spring-Mass Model with a Lieb Lattice Structure", J. Phys. Soc. Jpn. 89, 083702 (2020) by Hiromasa Wakao, Tsuneya Yoshida , Tomonari Mizoguchi , and Yasuhiro Hatsugai. Also arXiv:2005.00752.

投稿者 : hatsugai 投稿日時: 2020-06-18 07:34:20 (176 ヒット)

Linear electric circuits are one more non-quantum platform of the topological phenomena such as bulk-edge correspondence we have been working around. Then its non-hermitian extension with/without symmetry is surely of the important targets. We have here discussed mirror skin effects of the non-hermitian electric circuit where the boundary states dominate on the mirror symmetric lines. Also possible realization is proposed. Have a look at "Mirror skin effect and its electric circuit simulation" by Tsuneya Yoshida, Tomonari Mizoguchi, and Yasuhiro Hatsugai, Phys. Rev. Research 2, 022062(R) (2020) (Open access).

投稿者 : hatsugai 投稿日時: 2020-06-09 12:11:19 (184 ヒット)

We have been proposing a systematic construction scheme of flat bands by molecular orbitals (MO). Now it is extended for systems with non trivial topology where non trivial bands with non zero Chern numer may cross the flat bands although the Chern number of the flat band itself is vanishing. We have presented a various other examples such as the Haldane model and the Kane-Mele model of the MOs'. Have a look at Systematic construction of topological flat-band models by molecular-orbital representation" by Tomonari Mizoguchi and Yasuhiro Hatsugai, Phys. Rev. B 101, 235125 (2020) also arXiv:2001.10255.

投稿者 : hatsugai 投稿日時: 2020-03-15 00:55:42 (391 ヒット)

Topological phases are everywhere. Higher order topological phases are realized in a spring mass model on a Kagome lattice. Berry phases quantized in a unit of 2π/3 predict localized vibration modes near the corner of the system. This quantization is due to a symmetry protection. Have a look at our paper in Physical Review B. Most of the topological phenomena are realized in a mechanical analogue, which are much accessible without any real high-tech. Of course, it is still a non-trivial task.

    [0] バルクとエッジ
    [1] 集中講義
    [2] 原論文と解説
    [3] トポロジカル秩序とベリー接続:日本物理学会誌 「解説」 [JPS-HP] [pdf]
    [4] "Band gap, dangling bond and spin : a physicist's viewpoint" [pdf] [Web]
    科研費 1992年度:電子系スピン系におけるトポロジカル効果
    科研費 1994年度:物性論におけるトポロジーと幾何学的位相
    [1] MIT, Boston (2003)
    [2] APS/JPS March Meeting (2004)
    [3] JPS Fall meeting, JAPAN (2004)
    [4] APS/JPS March meeting (2005)
    [5] JPS Fall meeting (2005):Entanglement
    [6] Superclean workshop, Nasu (2006)
    [7] MPIPKS, Dresden (2006)
    [8] KEK, Tsukuba (2007)
    [9] ETH, Zurich (2008)
    [10] ICREA, Sant Benet (2009)
    [11] JPS Meeting, Kumamoto (2009)
    [12]HMF19, Fukuoka (2010)
    [13] NTU, Singapore (2011)
    [14] ICTP, Trieste (2011)
    [15] Villa conf., Orland (2012)
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