Compact localized states and flatband generators in one dimension

Autor: Oleg Gendelman, Wulayimu Maimaiti, Hee Chul Park, Alexei Andreanov, Sergej Flach
Rok vydání: 2016
Předmět:
DOI: 10.48550/arxiv.1610.02970
Popis: Flat bands (FB) are strictly dispersionless bands in the Bloch spectrum of a periodic lattice Hamiltonian, recently observed in a variety of photonic and dissipative condensate networks. FB Hamiltonians are finetuned networks, still lacking a comprehensive generating principle. We introduce a FB generator based on local network properties. We classify FB networks through the properties of compact localized states (CLS) which are exact FB eigenstates and occupy $U$ unit cells. We obtain the complete two-parameter FB family of two-band $d=1$ networks with nearest unit cell interaction and $U=2$. We discover a novel high symmetry sawtooth chain with identical hoppings in a transverse dc field, easily accessible in experiments. Our results pave the way towards a complete description of FBs in networks with more bands and in higher dimensions.
Comment: 11 pages, 4 figures
Databáze: OpenAIRE