Phase separation and pairing in coupled chains and planes

TL;DR

This paper investigates how coupling between chains or planes affects phase separation and pairing, revealing conditions that enhance superconductivity in a generalized $t-J$ model through numerical analysis.

Contribution

It introduces a generalized $t-J$ model for coupled chains or planes and analyzes the effects of interlayer coupling on phase separation and pairing.

Findings

Superconductivity signals are strongest at quarter filling.

Interlayer coupling can enhance intralayer pairing correlations.

Phase separation occurs near full interlayer separation.

Abstract

A generalization of the $t-J$ model in a system of two coupled chains or planes is studied by numerical diagonalization of small clusters. In particular, the effect of density fluctuations between these one- or two-dimensional coupled layerson intralayer phase separation and pairing is analyzed. The most robust signals of superconductivity are found at quarter filling for couplings just before the fully interlayer phase separated regime. The possibility of an enhancement of the intralayer superconducting pairing correlations by the interlayer couplings is investigated.