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arXiv · 2407.16415

Designing single and degenerate flat bands in the kagome lattice with long-range hopping

Yuta Taguchi·Motoaki Hirayama·Takashi Miyake
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Abstract

We investigate the electronic structure of the kagome lattice model with first, second, and two kinds of third nearest-neighbor hoppings. We reveal that by tuning the third nearest-neighbor hoppings, not only single flat band but also degenerate flat band can be created on the \Gamma - M line. We provide the detailed conditions to realize them. The coexistence of these bands can be almost realized near the fundamental band gap in graphene with triangular defects in a superhoneycomb arrangement. Furthermore, due to these flat bands, several sharp peaks appear in the optical conductivity. Our results strongly indicate that long-range electron hopping has a new possibility for designing electronic structures.

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Yuta Taguchi, Motoaki Hirayama, Takashi Miyake. 2024-07-23. Designing single and degenerate flat bands in the kagome lattice with long-range hopping. https://doi.org/10.1103/physrevb.111.115105

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