  We solve a very general two-channel fermion-boson model describing charge
transport within some background medium by means of a refined pseudo-site
density matrix renormalization group (DMRG) technique. Performing a careful
finite-size scaling analysis, we determine the ground-state phase diagram and
convincingly prove that the model exhibits a metal-insulator quantum phase
transition for the half-filled band case. In order to characterize the metallic
and insulating regimes we calculate besides the local particle densities and
fermion-boson correlation functions, the kinetic energy, the charge structure
factor, the Luttinger liquid charge exponent and the single-particle excitation
gap for a one-dimensional infinite system.
