Mott-Peierls Transition in the extended Peierls-Hubbard model

TL;DR

This study investigates the phase transitions in the extended Peierls-Hubbard model, revealing how electronic correlations influence insulator-metal transitions and the ground state evolution at various band fillings.

Contribution

It provides new insights into the ground state evolution and phase transitions in the extended Peierls-Hubbard model using DMRG, emphasizing the role of correlations in doped polyacetylene.

Findings

Ground state transitions from Mott-Peierls insulator to soliton lattice

Confirmation of insulator-metal transition at finite doping

Electronic correlations are crucial in theoretical models

Abstract

The one-dimensional extended Peierls-Hubbard model is studied at several band fillings using the density matrix renormalization group method. Results show that the ground state evolves from a Mott-Peierls insulator with a correlation gap at half-filling to a soliton lattice with a small band gap away from half-filling. It is also confirmed that the ground state of the Peierls-Hubbard model undergoes a transition to a metallic state at finite doping. These results show that electronic correlations effects should be taken into account in theoretical studies of doped polyacetylene. They also show that a Mott-Peierls theory could explain the insulator-metal transition observed in this material.