The one-dimensional t-J model coupled to adiabatic phonons: A numerical investigation

TL;DR

This study numerically explores the ground state of the one-dimensional t-J model with adiabatic phonons, revealing complex lattice distortions, charge-density-waves, and spin phases influenced by electron interactions.

Contribution

It provides a detailed numerical analysis of how electron-electron and electron-phonon interactions induce various lattice and magnetic phases in the t-J model.

Findings

Charge-density-waves and bond-order-waves form due to electron interactions.

Dimerization leads to an antiferromagnetic Mott insulator.

Tetramerization results in a spin-Peierls phase.

Abstract

The ground state of the one-dimensional t-J model coupled with phonons in the adiabatic limit is numerically investigated by use of the Lanczos technique at quarter filling. Due to the interplay between the electron-electron Coulomb repulsion and electron-phonon interaction, this model shows a sequence of lattice distortions leading to the formation of charge-density-waves and bond-order-waves. Moderate electron-electron and electron-lattice coupling may lead to coexistence of dimerization and tetramerization in the distortion pattern. Dimerization leads to the formation of an "antiferromagnetic" Mott insulator, while tetramerization gives rise to a spin-Peierls phase. By increasing the super-exchange coupling, antiferromagnetism is inhibited due to the change of the distortion periodicity.