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arXiv · 2412.18965

Flat Bands and Compact Localised States: A Carrollian roadmap

Nisa Ara·Aritra Banerjee·Rudranil Basu·Bhagya Krishnan
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Abstract

We show how Carrollian symmetries become important in the construction of one-dimensional fermionic systems with all flat-band spectra from first principles. The key ingredient of this construction is the identification of Compact Localised States (CLSs), which appear naturally by demanding $\textit{supertranslation}$ invariance of the system. We use CLS basis states, with inherent $\textit{ultra-local}$ correlations, to write down an interacting theory which shows a non-trivial phase structure and an emergent Carroll conformal symmetry at the gapless points. We analyze this theory in detail for both zero and finite chemical potential.

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Nisa Ara, Aritra Banerjee, Rudranil Basu, Bhagya Krishnan. 2024-12-25. Flat Bands and Compact Localised States: A Carrollian roadmap. https://doi.org/10.21468/scipostphys.19.2.046

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