We report measurements of the current noise generated by the optimally doped, x=0.15, Au−La2−xSrxCuO4 junctions. For high transmission junctions on (110) surface, we observed split zero-bias conductance peak (ZBCP), accompanied by enhanced shot noise. We attribute the enhanced noise to the Cooper pair transport through the junction. The ZBCP disappears and the noise decreases to the one expected for the charge e with heating at temperatures well below Tc, and at voltages much smaller than the bulk superconducting gap, setting a new energy scale of 0.5 mV. We attribute this scale to the existence of an idxy or is order parameter at the sample surface.
@article{arxiv.1707.00344,
title = {Zero Energy States at a Normal--Cuprate-Superconductor Interface Probed by Shot Noise},
author = {O. Negri and M Zaberchik and A. Keren and M. Reznikov},
journal= {arXiv preprint arXiv:1707.00344},
year = {2018}
}