Probing the pairing symmetry and pair charge stiffness of doped $t-J$ ladders

TL;DR

This study uses numerical simulations to investigate the pairing symmetry and superconducting properties of doped $t-J$ ladders, revealing how doping influences pair parity and the suppression of superconductivity associated with stripe formation.

Contribution

It provides a phase-sensitive numerical analysis of pairing symmetry and pair charge stiffness in doped $t-J$ ladders, connecting doping levels with changes in pair parity and superconductivity.

Findings

Pair parity changes from minus to plus with increased doping.

Superconductivity is suppressed where static stripes form.

Results align with bosonization and RG predictions.

Abstract

We perform the numerical equivalent of a phase sensitive experiment on doped $t-J$ ladders. We apply proximity effect fields with different complex phases at both ends of an open system and we study the transport of Cooper pairs. Measuring the response of the system and the induced Josephson current, Density Matrix Renormalization Group calculations show how, depending on the doping fraction, the rung-leg parity of the pair field changes from minus to plus as the density of holes is increased. We also study the pair charge stiffness, and we observe a supression of the superconductivity in the region where static stripes appear. We compare our results with predictions from bosonization and renormalization group analysis.