The Gap Function Phi(k,w) for a Two-leg t-J Ladder and the Pairing Interaction

TL;DR

This paper investigates the pairing interaction in a doped 2-leg t-J ladder using the gap function phi(k,omega) from Lanczos calculations, revealing a local, retarded near-neighbor coupling influenced by magnon-hole-pair energies.

Contribution

It introduces a detailed analysis of the pairing interaction's spatial and temporal structure based on the gap function in a doped t-J ladder.

Findings

The pairing interaction is a local near-neighbor coupling.

It is retarded and influenced by the energy of S=1 magnon-hole-pairs.

The interaction spans a frequency region of the order of the bandwidth.

Abstract

The gap function phi(k,omega), determined from a Lanczos calculation for a doped 2-leg t-J ladder, is used to provide insight into the spatial and temporal structure of the pairing interaction. It implies that this interaction is a local near-neighbor coupling which is retarded. The onset frequency of the interaction is set by the energy of an S=1 magnon-hole-pair and it is spread out over a frequency region of order the bandwith.