Reduction of non-Hermitian 1D topology with interaction

Reduction of non-Hermitian 1D topology with interaction

Topological protection for topological systems may change by the inclusion of particle-particle interaction, which is known as "reduction phenomena." Here we have pointed out its possibilities for 1-d...
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TTQM2022

TTQM2022

Swiss-Japan bilateral workshop "Trends in the Theory of Quantum Materials 2022 (TTQM2022)" @ ETH, Zurich, is ready after a three-year break due to COVID-19. Thanks for the arrangement!
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Bulk-edge correspondence in electric circuits of topological pump

Bulk-edge correspondence in electric circuits of topological pump

One of the recent wisdom for topological phases is the use of a classical system as a quantum simulator. The Hofstadter butterfly associated with topological phase transitions is realized in electric ...
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日本物理学会2022年秋

講演番号 登録番号 タイトル 著者 所属 領域 13pPSB-31 982 固有値の非線形性を持つ系のバルク境界対応 磯部拓磨, 吉田恒也, 初貝安弘 筑波大数理 領域4 15aH131-8 887 一般化された回転対称性のある系での例外点と判別式指標 若尾洋正, 吉田恒也, 初貝安弘 筑波大数理 領域4 15aH131-9 1257 一次元点ギャップトポロジーに対する強相関効果 吉田恒也, 初貝...
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Adiabatic connection with spin

Adiabatic connection with spin

Adiabatic connection of the gapped many-body states is a conceptual background of the topological phases. Historical and more than successful examples are given by various fractional quantum Hall stat...
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BEC seminar :工藤耕司氏 (Penn State) Aug.10, 2022

BEC seminar :工藤耕司氏 (Penn State) Aug.10, 2022

On Aug.10 (Wed) 2022 at 11:am Japan time, Koji Kudo at Penn State will be telling us about his recent study by a title : "Exactly solvable model for non-Abelian quasiparticle states." Join us on zoom....
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“b 2– 4 ac” formula with rotation symmetry

“b 2– 4 ac” formula with rotation symmetry

The discriminant is a generalization of the "b 2- 4 ac" formula that everybody knows, which tells us the degeneracy of the (secular) equation. Then it is natural the discriminant is useful for the stu...
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Random flatbands are special

Random flatbands are special

Recent wisdom for the construction of flat bands is applicable even with randomness. Characterization of special features of the random flat bands has been successfully done by using machine learning....
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APS March meeting 2022

APS March meeting, March 14-18 2022, Chicago USA
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日本物理学会2022年春

  講演番号 登録番号 タイトル 著者 所属 領域 15aE22-8 529 拡張ボースハバード模型におけるトポロジカルポンプとバルクエッジ対応 久野義人A, B, 初貝安弘A 筑波大数理A, 秋田大B 領域1 15aT24-10 2043 カゴメ格子上の熱伝導 牧野柊星, 福井隆裕, 吉田恒也A, 初貝安弘A 茨城大, 筑波大A 領域4 17pPSE-3 496 光メタマテリアルにおけ...
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Heat escapes fast due to bulk-edge correspondence

Heat escapes fast due to bulk-edge correspondence

Analyzing a diffusion equation of alternative metals, rapid heat conduction to the heat bath due to edge states is predicted. The edge states are predicted by the bulk topological invariant as a typic...
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Exact correlation of correlation

Exact correlation of correlation

Once one admits the electronic state is described by the molecular-orbitals (MOs), the system has flat bands when the number of MOs is less than the total number of atoms. Then it is natural the elect...
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Discriminant and symmetry

Discriminant and symmetry

As widely accepted, the degeneracy of eigenvalues of the Hamiltonian is a singular point, which is the source of the non-trivial topology. Then it is more than natural that the discriminant of the sec...
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Non Hermitian topology in game theory

Non Hermitian topology in game theory

The use of topological invariants for the characterization of material phases has been quite successful. Non-trivial topology is reflected by physical observables near the boundaries of systems as a b...
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First/second order topology in honeycomb lattice

First/second order topology in honeycomb lattice

The Haldane model with Kekulè distortion possesses various phases characterized by different topology with specific boundary states. Competition between the 1st/2nd order topology (1D/0D boundary stat...
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Flux attachement and bulk-edge correspondence

Flux attachement and bulk-edge correspondence

Adiabatic insertion of the Aharonov-Bohm flux through two pinholes introduces charge transport between them when the system is topologically non-trivial. This is the Laughlin argument. The defects/pin...
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第16回(2022年)日本物理学会若手奨励賞

助教の吉田恒也さんが第16回(2022年)日本物理学会若手奨励賞 (Young Scientist Award of the Physical Society of Japan)を受賞しました。 非エルミート性が誘起する強相関トポロジカル現象に関する先駆的研究 "Non-Hermitian perspective of the band structure in heavy-fermion sys...
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BEC Seminar 14:00-15:00 11月26日(金)2021年:松木義幸さん(大阪大学)

11月26日(金)に松木 義幸さん(大阪大学)さんに最近のご研究に関してお話し頂きます。(Zoom)。よろしくお願いいたします。ご興味のあります方は初貝(クリックしてください)までご連絡下さい。 "Fractal defect states in the Hofstadter butterfly"
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Multi-fold EP protected by anti-unitary symmetry

Multi-fold EP protected by anti-unitary symmetry

Generic degeneracy of a non-hermitian hamiltonian implies a set of the eigenvectors is not enough to span the total linear space. One needs to extend the idea of the eigenstates to the generic ones, w...
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3D HOTI of Hubbard model by  negative sign free quantum Monte Carlo

3D HOTI of Hubbard model by negative sign free quantum Monte Carlo

Corner states of the breezing Pyrochlore lattice are protected by the Z4 symmetry as a typical example of the bulk-edge/boundary correspondence using Z4 Berry phase. With on-site Coulomb interaction, ...
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