Possible d+id scenario in La_{2-x}Sr_{x}CuO_4 by point-contact measurements

TL;DR

This study uses point-contact measurements to explore the superconducting gap symmetry in La_{2-x}Sr_{x}CuO_{4}, providing evidence for a nodeless d_{x^2-y^2}+id_{xy} wave pairing and analyzing its doping dependence.

Contribution

It offers new experimental support for a complex d+id pairing symmetry in LSCO, highlighting the doping evolution of the subdominant gap component.

Findings

Evidence for d+id wave symmetry from conductance curves

Doping dependence of the d_{xy} gap component analyzed

Comparison with theoretical models discussed

Abstract

We analyze the results of point-contact measurements in La_{2-x}Sr_{x}CuO_{4} (LSCO) previously reported as a clear evidence of the separation between gap and pseudogap in this copper oxide. Here we show that, in addition to this, the conductance curves of our point-contact junctions -- showing clear Andreev reflection features -- can be interpreted as supporting a nodeless d_{x^2-y^2}+id_{xy}-wave symmetry of the gap in LSCO. The results of our analysis, in particular the doping dependence of the subdominant d_{xy} gap component, are discussed and compared to the predictions of different theoretical models.