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初貝 安弘
筑波大学
数理物質系物理学域長
筑波大学大学院
数理物質科学研究科
物理学専攻 教授,物理学専攻長
初貝写真
Yasuhiro-Nov11-2009
会議 & 研究会
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投稿者 : hatsugai 投稿日時: 2016-12-01 16:41:58 (519 ヒット)

1 千葉市科学館 平成 28 年度 「大人が楽しむ科学教室 ~量子力学シリーズ~」12月4日(日)(4)「トポロジカル物質の母としてのグラフェン」

2 千葉市科学館 平成 28 年度 「大人が楽しむ科学教室 ~量子力学シリーズ~」12月17日(土)(7)「物理学における対称性の役割とトポロジカル相」


投稿者 : hatsugai 投稿日時: 2016-09-16 10:55:24 (616 ヒット)

Our paper on a photonic system in 3D which has the Weyl points due to breaking inversion is published in Phys. Rev. B as an edtors' suggestsion. See also highlights. The Weyl points are characterized as the topopoligical critial points of the sliced 2D system which has a non trivial Chern number (section Chern number) with jumps. Momentum selective edge states propagating near the boundaries are discussed as a typical example of the bulk-edge correspondence. Have a look at !


投稿者 : hatsugai 投稿日時: 2016-05-12 09:29:05 (2601 ヒット)

We are organizing a workshop on the bulk-edge correspondence in relation to cold atoms and ARPES ( theories as well) as a YITP workshop ( Yukawa Institute of theoretical physics) in Kyoto Sep.27-30, 2016. Its registration will be open soon. Stay tuned. [YITP site] . [Direct link].


投稿者 : hatsugai 投稿日時: 2016-01-16 17:16:48 (1354 ヒット)

Topological pump, proposal by Thouless and just recently realized experimeatally in Kyoto and Munich independently, is revisited from the bulk-edge correspondence (BEC). It's typically described by well known Harper equation as in QHE but the view point of BEC supplies quite different physical / mathematical structure. Pumped charge is carried by bulk but its quantization is guaranteed by the topological number defined by a singular motion of the center of mass caused by edge states. However this singular motion can not be observed in reality by a pumping of finite speed.The edge states are hidden! Counting the topological number by singularities of the spectral flow is a standard technique in the discussion of the Atiyah-Patodii-Singer index theorem. The same counting appears in the BEC in the pumping. It's a unexpected surprise. Have a look at arXiv:1601.03537, Phys. Rev. B94, 041102(R) (2016)


投稿者 : hatsugai 投稿日時: 2016-01-16 17:16:20 (892 ヒット)

Our paper is now online. Topology is not only for quantum world. Localised modes near the system boundaries also exist in a classical system that is predicted by bulk. This is the bulk-edge correspondence originally discussed in quantum systems such as quantum (spin) Hall states and graphene. Still this idea is valid in classical world. We discussed topological phenomena in mechanics for point particles connected with springs in a honeycomb shape. Also topological phase transitions associated with its tension is clearly demonstrated as a time evolution of the localized modes. [arXiv:1505.06679]


投稿者 : hatsugai 投稿日時: 2015-09-14 19:50:18 (1368 ヒット)

We are organizing an international workshop on the bulk-edge correspondence / topological phases  Sep. 27-29 (2015) in Tokyo (Myogadani) supported by KAKENHI (JSPS research funding). Tentative program is ready and on the net.


投稿者 : hatsugai 投稿日時: 2015-09-14 19:44:26 (870 ヒット)

Looking at the Landau-Lifshitz again for mechanics, a simple classical system is redescribed topologically. Hannay angle as a classical correspondent of the Berry phase is discussed in relation to the symmetry protection and the bulk-edge correspondence. (arxiv:1508.06946)


投稿者 : hatsugai 投稿日時: 2015-06-18 11:46:16 (771 ヒット)

Our paper "Topological Order Parameters of the Spin-1/2 Dimerized Heisenberg Ladder in Magnetic Field" is published in Phys. Rev.B . [arXiv:1412.7901] . Fractinal quantization of the Berry phase as pi/4 is quite useful for  characterization of some spin ladder with magnetic field.


投稿者 : hatsugai 投稿日時: 2015-06-07 05:55:51 (849 ヒット)

千葉大の中山隆史先生ご紹介にて「バルクエッジ対応の物理の多様性と普遍性」として平成27年7月8日-9日に集中講義をやります。


投稿者 : hatsugai 投稿日時: 2015-03-25 05:33:11 (726 ヒット)

チャーン数に関する私たちの論文 "Chern Numbers in Discretized Brillouin Zone: Efficient Method of Computing (Spin) Hall Conductances" ( T. Fukui, Y. Hatsugai, H. Suzuki ) が第20回(2015年)日本物理学会論文賞に選ばれました。ありがとうございました。


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現在の時刻
今年もやります。まずは量子力学3. 冬は 統計力学2. 平成30年の新年あけましておめでとうございます。今年もあと225日!
最新ニュース
投稿者 : hatsugai 投稿日時: 2018-05-08 12:09:09 (86 ヒット)

Atsuo Shitade (RIKEN, CEMS) will give a talk on May 30 (2018) with a title "Theory of Orbital Magnetic Quadrupole Moment and Magnetoelectric Susceptibility". The detail is here.


投稿者 : hatsugai 投稿日時: 2018-04-20 18:51:10 (83 ヒット)

ありがとうございました: 平成30年度科学技術分野の文部科学大臣表彰,科学技術賞(研究部門)初貝安弘「トポロジカル相でのバルクエッジ対応の研究」 [PDF]
筑波大学広報


投稿者 : hatsugai 投稿日時: 2017-12-26 01:33:43 (366 ヒット)

最近の研究成果トピックスとして2017年度の科研費ニュース vol.3 にトポロジカル相とバルク・エッジ対応の関係の解説を我々の研究の背景として書きました。予備知識は不要ですのでご興味のある方はご覧下さい。「トポロジカル物質におけるバルク・エッジ対応」


投稿者 : hatsugai 投稿日時: 2017-12-22 19:52:51 (324 ヒット)

Michel Fruchart (Instituut-Lorentz Universiteit, Leiden) will give a talk on Jan.9 (2018), 10:30 am at Rm. B602 by the title Topology of effective evolutions: oriented scattering networks and the phase rotation symmetry


投稿者 : hatsugai 投稿日時: 2017-12-22 11:33:02 (328 ヒット)

Christopher Mudry (Paul Scherrer Institute, Switzerland) gives a talk by the title "Abelian topological order in three-dimensional space" at Rm. B602 from 14:00 on Dec.28, (2017). The detail is here


    検索
    バルク・エッジ対応
    [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]
    トポロジカル相
    [0]昔の科研費
    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
    私の講演ファイルのいくつか
    [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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