Recent News
- Recent progress in Quantum Computing: Talk by Nobuyuki Yoshioka
- Yutaka Shikano will tell us about observation of identical particles
- 22nd International Conference on Recent Progress in Many-Body Theories (RPMBT22)
- 2024 JPS Fall meeting
- Z3 Berry phases for quantum spins
- Non-uniform flux and particle blocking
- Our new member, Kazuki Sone, will tell us on edge states of non-linear systems
- Funding 2024
- Bulk-edge correspondence for energy dependent systems/nonlinear eigen value problems
- SKCM² Spring Symposium: Nara, Japan
- APS March meeting 2024
- Bulk-edge correspondence (Encyclopedia of condensed matter physics, 2nd Ed.)
- TTQM2023 Kashiwa
- The Physical Society of Japan, Annual meeting 9/16-9/19 (2023), Tohoku Univ.
- Nontrivial Topology of Nontopological Nonlinear Waves
- Shiro Sakai will tell us on hyperuniformity !
- Heat carrying corner states of breathing Kagome
- Z2× Z2 symmetry and Z4 quantization in bosonic ladders
- Hidenori Fukaya will be telling us on dyon & topological insulators
- Negative index photonic crystal induces non hermitian physics
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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
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
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
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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Young Scientist Award of the Physical Society of Japan (2022)
Tsuneya Yoshida (assistant Prof.) is awarded the "Young Scientist Award of the Physical Society of Japan (2022)" Pioneering works on non-Hermitian strongrly correlated phenomena "Non-He...
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BEC Seminar 14:00-15:00 Nov.26 (2021) Yoshiyuki Matsuki
Yoshiyuki Matsuki will be telling us on their recent work. (Zoom)。Join us by contacting Y. Hatsugai. "Fractal defect states in the Hofstadter butterfly"
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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
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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Bulk-edge correspondence of interacting bosonic pump
Topological (adiabatic) pumps are typical problems where the bulk-edge correspondence is justified. The Chern number of the bulk and the behavior of the edge states are linked intimately. As for most ...
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Hofstadter’s butterfly and TKNN integers
Hofstadter's butterfly ＆ TKNN integers (Chern numbers)
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Non real energies for Hermitian problems
Eigenvalues may not be always real for generalized eigenvalue problems even if the Hamiltonian and overlap matrices are both Hermitian. When the overlap is associated with a norm of physical state, th...
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Multiple quantum scars and dynamics
A flat band system with interaction that possesses a single "quantum scar", which we have proposed in Kuno-Mizoguchi-Hatsugai, Phys. Rev. B 102, 241115(R) (2020), is extended to a system wit...
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One more topological phase with chiral edge states
Bulk-edge correspondence is universal. We do find a novel playground of the chiral edge states protected by bulk topology. It is in the evolutionary game theory realized in a kagome network. The paper...
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Flat bands of COF/MOF in any dimension
Covalent/Metal-organic framework (COF/MOF) is a 2D/3D network compound of organic molecules (linkages) connected by linker molecules. This material possesses a set of flat bands (at least in a tight-b...
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Flat bands and spin-1 Dirac cone
We are proposing one more lattice structure with frustration that hosts flat bands, square-Kagome lattice. Using a molecular orbital representation, its flat band and flat dispersion only in some spec...
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Reduction of non-hermitian topology in 0-D
Many body interactions may modify the topology of physical systems. We have discussed it for a simple 0-D system with non-hermitian hamiltonian. Have a look at our recent paper, "Correlation effe...
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Non-real energies in real world
Our paper on non-real things has been picked up by JPS Hot Topics. It's real.
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Plateau transitions of quantum spin chain
Quantum mechanics tells us particles are waves at the same time. One may then naively expect that the quantum state is extended, especially with translational invariance. However, it is not always tru...
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Symmetries and square-root operations
Motivated by the relation between the Dirac/Schrodinger hamiltonians, the square root topological phase (SRTI) has been discussed in several cases recently. Here the roles of symmetries in SRTI are fo...
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Square-root topological semimetals
We propose topological semimetals generated by the square-root operation for tight-binding models in two and three dimensions, which we call square-root topological semimetals. The square-root topolog...
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