Localization by bichromatic potentials versus Anderson localization

Abstract

The one-dimensional propagation of waves in a bichromatic potential may be modeled by the Aubry-Andr\'e Hamiltonian. The latter presents a delocalization-localization transition, which has been observed in recent experiments using ultracold atoms or light. It is shown here that, in contrast to Anderson localization, this transition has a classical origin, namely the localization mechanism is not due to a quantum suppression of a classically allowed transport process. Explicit comparisons with the Anderson model, as well as with experiments, are done.