Metal–insulator transition in the acentric Hubbard ladders at quarter filling: a self-doping mechanism

Abstract

We examine the acentric Hubbard ladder model at quarter filling, using the mean-field approximation, the weak-coupling theory, the Bethe-ansatz method, and the DMRG technique. This model is the simplest quasi-1D model where the metal–insulator transition is realized by a self-doping mechanism. We clarify the ground-state properties of the model and find that the reentrant insulator–metal–insulator transition occurs with increasing U/ t ∥.