Superconducting gap for a 2-leg t-J ladder

TL;DR

This paper investigates the superconducting gap in a 2-leg t-J ladder at 1/8 doping using exact diagonalization, proposing a new expression for the gap and analyzing its frequency dependence and the role of low-energy spin modes.

Contribution

It introduces a numerically tractable expression for the superconducting gap and explores the influence of low-energy gapped spin modes in a 2-leg t-J ladder.

Findings

Proposed a new expression for the superconducting gap.

Determined the frequency dependence of the gap's real and imaginary parts.

Analyzed the role of low-energy gapped spin modes.

Abstract

Single-particle diagonal and off-diagonal Green's functions of a 2-leg t-J ladder at 1/8-doping are investigated by Exact Diagonalisations techniques. A numerically tractable expression for the superconducting gap is proposed and the frequency dependence of the real and imaginary parts of the gap are determined. The role of the low-energy gapped spin modes whose energies are computed by a (one-step) Contractor Renormalization procedure are discussed.