Phase separation near half-filling point in superconducting compounds

TL;DR

This paper models superconducting ceramics near half-filling using an extended Hubbard Hamiltonian, analyzing how various interactions influence phase separation between antiferromagnetism and superconductivity, with results compared to experimental data.

Contribution

It introduces a comprehensive model incorporating multiple interactions to study phase separation in superconducting compounds near half-filling.

Findings

Interactions significantly affect phase separation near half-filling.

Model results align with experimental data for YBaCuO and NdCeCuO.

Both AF and SC phases coexist depending on interaction strengths.

Abstract

We present the model of superconducting ceramics using the single band extended Hubbard Hamiltonian. We investigate the simultaneous presence of antiferromagnetism (AF) and d-wave superconductivity (SC) in the coherent potential (CP) approximation applied to the on-site Coulomb repulsion $U$. We consider the hopping interaction, $\Delta t$, the inter-site charge-charge interaction, $V$, (creating SC), and the single site Hund's type exchange interaction, $F_{in}$, (creating AF). The influence of these interactions on the separation of superconducting and antiferromagnetic phases near the half-filling point is investigated. Results are compared with the experimental data for YBaCuO and NdCeCuO compounds.