Correlation-induced metal insulator transition in a two-channel fermion-boson model

Abstract

We investigate charge transport within some background medium by means of an effective lattice model with a novel form of fermion-boson coupling. The bosons describe fluctuations of a correlated background. By analyzing groundstate and spectral properties of this transport model, we show how a metal-insulator quantum phase transition can occur for the half-filled band case. We discuss the evolution of a mass-asymmetric band structure in the insulating phase and establish connections to the Mott and Peierls transition scenarios.

4 pages, 4 figures, 1 table, revised version accepted for publication in Phys. Rev. Lett