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arXiv · 2308.14997

Symmetry-protected flatband condition for Hamiltonians with local symmetry

Jung-Wan Ryu·Alexei Andreanov·Hee Chul Park·Jae-Ho Han
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Abstract

We derive symmetry-based conditions for tight-binding Hamiltonians with flatbands to have compact localized eigenstates occupying a single unit cell. The conditions are based on unitary operators commuting with the Hamiltonian and associated with local symmetries that guarantee compact localized states and a flatband. We illustrate the conditions for compact localized states and flatbands with simple Hamiltonians with given symmetries. We also apply these results to general cases such as the Hamiltonian with long-range hoppings and higher-dimensional Hamiltonian.

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Jung-Wan Ryu, Alexei Andreanov, Hee Chul Park, Jae-Ho Han. 2023-08-29. Symmetry-protected flatband condition for Hamiltonians with local symmetry. https://doi.org/10.1088/1751-8121%2Fad909d

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