Novel Density-Wave States of Two-Band Peierls-Hubbard Chains

TL;DR

This paper systematically explores and classifies various density-wave states in a one-dimensional two-band Peierls-Hubbard model, revealing potential novel phases influenced by interactions and band filling.

Contribution

It introduces a comprehensive symmetry-based analysis of broken-symmetry solutions and maps out the ground-state phase diagram for the model.

Findings

Identification of all regular-density-wave solutions with q=0 or q=π

Numerical phase diagram revealing diverse ground states

Discussion of potential novel density-wave states

Abstract

Based on a symmetry argument we systematically reveal Hartree-Fock broken-symmetry solutions of the one-dimensional two-band extended Peierls-Hubbard model, which covers various materials of interest such as halogen-bridged metal complexes and mixed-stack charge-transfer salts. We find out all the regular-density-wave solutions with an ordering vector $q=0$ or $q=\pi$. Changing band filling as well as electron-electron and electron-phonon interactions, we numerically inquire further into the ground-state phase diagram and the physical property of each state. The possibility of novel density-wave states appearing is argued.