Quantum transport in flat bands and supermetallicity
G. Bouzerar, Didier Mayou
Abstract
Quantum physics in flat-band (FB) systems embodies a variety of exotic phenomenon and even counterintuitive features. The quantum transport in several graphene based compounds that exhibit a flat band and a tunable gap is investigated. Despite the localized nature of the FB states and a zero group velocity, a supermetallic (SM) phase at the FB energy is revealed. The SM phase is robust against the inelastic scattering strength and controlled only by the interband transitions between the FB and the dispersive bands. The SM phase appears insensitive and quasi-independent of the gap amplitude and nature of the lattice (disordered or nanopatterned). The universal nature of the unconventional FB transport is illustrated with the case of electrons in the Lieb lattice.