Indications of d_{x^2 - y^2} Superconductivity in the Two Dimensional t-J Model

TL;DR

This paper provides numerical evidence of d_{x^2 - y^2} superconductivity in the two-dimensional t-J model at half-filling, supported by various indicators and a proposed spin dimer liquid state explanation.

Contribution

It demonstrates strong superconducting correlations in the 2D t-J model at specific densities using multiple numerical indicators, and presents a phase diagram.

Findings

Strong signals of d_{x^2 - y^2} superconductivity at half-filling

Superconductivity explained by a spin dimer liquid state

A phase diagram of the 2D t-J model is provided

Abstract

Superconducting correlations in the two dimensional ${\rm t-J}$ model at zero temperature are evaluated using numerical techniques. At the fermionic density $\langle n \rangle \sim 1/2$, strong signals of $\dx2y2$ superconductivity were observed in the ground state. These conclusions are based on a study of static pairing correlations, the Meissner effect, flux quantization, and other indicators of superconductivity. It is argued that these results can be explained using a spin dimer ``liquid'' state. A phase diagram of the two dimensional ${\rm t-J}$ model is presented.