Chiral Flat Bands: Existence, Engineering and Stability
Abstract
We study flat bands in bipartite tight-binding networks with discrete translational invariance. Chiral flat bands with chiral symmetry eigenenergy E = 0 and host compact localized eigenstates for finite range hopping. For a bipartite network with a majority sublattice chiral flat bands emerge. We present a simple generating principle of chiral flat band networks and as a showcase add to the previously observed cases a number of new potentially realizable chiral flat bands in various lattice dimensions. Chiral symmetry respecting network perturbations - including disorder and synthetic magnetic fields - preserve both the flatband and the modified compact localized states. Chiral flatbands are spectrally protected by gaps, and pseudogaps in the presence of disorder due to Griffiths effects.
Keywords
Cite
@article{arxiv.1706.02294,
title = {Chiral Flat Bands: Existence, Engineering and Stability},
author = {Ajith Ramachandran and Alexei Andreanov and Sergej Flach},
journal= {arXiv preprint arXiv:1706.02294},
year = {2017}
}