An effective 1-band model for the cuprate superconductors

TL;DR

This paper derives an effective 1-band Hubbard model from the copper-oxygen Hamiltonian to better understand the complex phases in cuprate superconductors, highlighting the unique properties of CuO2 planes.

Contribution

It provides an analytical derivation of an extended 1-band Hubbard model from the copper-oxygen Hamiltonian using a canonical transformation.

Findings

Model supports various phases including checkerboard, stripes, and antiferromagnetism

Eliminates oxygen sites to simplify the Hamiltonian

Helps understand the unique properties of CuO2 planes

Abstract

Starting from the copper-oxygen Hamiltonian of the CuO2 planes, we derive analytically an extended 1-band Hubbard Hamiltonian for the electrons on copper sites, through a canonical transformation which eliminates the oxygen sites. The model sustains a variety of phases : checkerboard states, stripes, antiferromagnetism, local pairs and mixtures thereof. This approach may be helpful in understanding what is so special about the CuO2 planes, as opposed to other compounds.