Superconductivity in the Cuo Hubbard Model with Long-Range Coulomb Repulsion

TL;DR

This paper investigates a multiband CuO Hubbard model with long-range Coulomb interactions, revealing charge transfer, phase stability changes, and superfluidity formation through numerical analysis, primarily in one-dimensional systems.

Contribution

It introduces a comprehensive model including long-range Coulomb interactions and demonstrates their effects on charge transfer, phase stability, and superconductivity in cuprate-like systems.

Findings

Charge transfer from copper to oxygen occurs with increasing LR interaction.

Phase separation becomes unstable, replaced by a uniform doubly occupied oxygen state.

Superfluid condensate forms as holes become mobile, indicating superconductivity.

Abstract

A multiband CuO Hubbard model is studied which incorporates long-range (LR) repulsive Coulomb interactions. In the atomic limit, it is shown that a charge-transfer from copper to oxygen ions occurs as the strength of the LR interaction is increased. The regime of phase separation becomes unstable, and is replaced by a uniform state with doubly occupied oxygens. As the holes become mobile a superfluid condensate is formed, as suggested by a numerical analysis of pairing correlation functions and flux quantization. Although most of the calculations are carried out on one dimensional chains, it is