Temperature and magnetic field dependent tunneling spectroscopy of PtIr/Sr$_{0.9}$La$_{0.1}$CuO$_2$ point contact

TL;DR

This study uses tunneling spectroscopy with PtIr contacts to investigate the superconducting gap symmetry of Sr$_{0.9}$La$_{0.1}$CuO$_2$ under varying temperature and magnetic field conditions, finding evidence against d-wave symmetry.

Contribution

It provides the first detailed tunneling spectroscopy analysis of Sr$_{0.9}$La$_{0.1}$CuO$_2$ and challenges the assumption of d-wave pairing symmetry in this material.

Findings

No zero-bias conductance peaks observed.

Superconducting gap fits s-wave symmetry.

Results exclude d-wave and conventional phonon pairing.

Abstract

Low barrier quasiparticle tunneling spectroscopy on Sr$_{0.9}$La$_{0.1}$CuO$_2$ has been studied with PtIr/Sr$_{0.9}$La$_{0.1}$CuO$_2$ point contacts at various temperatures and magnetic fields. No zero-bias conductance peaks are observed. By fitting tunneling conductance to Blonder-Tinkham-Klapwijk theory, the temperature dependent s-wave superconducting gaps are obtained. The present results exclude the possibility of d-wave symmetry for the pair gap in Sr$_{0.9}$La$_{0.1}$CuO$_2$, and do not support the conventional phonon mediated pairing in this system either.