The superconducting gap function of Sr2RuO4 was investigated by means of quasiparticle reflection and transmission at the normal conductor-superconductor interface of Sr2RuO4-Pt point contacts. We found two distinguishly different types of dV/dI vs V spectra either with a double-minimum structure or with a zero-bias conductance anomaly. Both types of spectra are expected in the limit of high and low transparency, respectively, of the interface barrier between a normal metal and a spin-triplet superconductor. Together with the temperature dependence of the spectra this result strongly supports a spin-triplet superconducting order parameter for Sr2RuO4.
@article{arxiv.cond-mat/9907267,
title = {Spin-triplet superconductivity in Sr$_2$RuO$_4$ probed by Andreev reflection},
author = {F. Laube and G. Goll and H. v. Löhneysen and M. Fogelström and F. Lichtenberg},
journal= {arXiv preprint arXiv:cond-mat/9907267},
year = {2009}
}