Supermetallic and Trapped States in Periodically Kicked Lattices

TL;DR

This paper investigates periodically driven lattices with two spatial periodicities, revealing super metallic states with enhanced wave spreading and trapped states with inhibited transport, linked to topological dispersion and flat bands.

Contribution

It uncovers super metallic and trapped states in driven lattices, demonstrating their topological origin and relation to flat band phases, a novel insight into quantum transport phenomena.

Findings

Resonant super metallic states with universal dispersion curves.

Anti-resonant trapped states with dips in entropy.

Sequence of gapped phases with flat band states.

Abstract

A periodically driven lattice with two commensurate spatial periodicities is found to exhibit super metallic states characterized by enhancements in wave packet spreading and entropy. These resonances occur at critical values of parameters where multi-band dispersion curves reduce to a universal function that is topologically a circle and the effective quantum dynamics describes free propagation. Sandwiching every resonant state are a pair of anti-resonant {\it trapped states} distinguished by dips in entropy where the transport, as seen in the spreading rate, is only somewhat inhibited. Existing in gapless phases fo the spectrum, a sequence of these peaks and dips are interspersed by gapped phases assocated with flat band states where both the wave packet spreading as well as the entropy exhibit local minima.