Metal-insulator transition in the Edwards model

TL;DR

This paper investigates a two-channel fermion-boson transport model revealing a metal-insulator transition at half-filling, characterized by a Luttinger liquid to charge density wave phase change, using advanced numerical methods.

Contribution

It introduces a novel fermion-boson coupling model and demonstrates the metal-insulator transition through comprehensive numerical analysis.

Findings

Identifies a quantum phase transition at half-filling

Characterizes the metallic phase as a Luttinger liquid

Shows the insulating phase as a charge density wave

Abstract

To understand how charge transport is affected by a background medium and vice versa we study a two-channel transport model which captures this interplay via a novel, effective fermion-boson coupling. By means of (dynamical) DMRG we prove that this model exhibits a metal-insulator transition at half-filling, where the metal typifies a repulsive Luttinger liquid and the insulator constitutes a charge density wave. The quantum phase transition point is determined consistently from the calculated photoemission spectra, the scaling of the Luttinger liquid exponent, the charge excitation gap, and the entanglement entropy.