Persistent current in a two-band disordered interacting one-dimensional ring

Using numerical exact diagonalization and analytical variational calculations, we examine the effect of an electronic two-band structure on the persistent current of an interacting disordered one-dimensional ring. Several different features in comparison to a single band model are encountered. Among them are a transition in the magnitude of current for a critical ratio of the hopping elements in the two bands, and a large increase in the rms value of the persistent current for certain values of interaction and disorder. Possible experimental implications are discussed.