Suppression of spontaneous currents in Sr2RuO4 by surface disorder

A major challenge to the chiral p-wave hypothesis for the pairing symmetry of the unconventional superconductor Sr2RuO4 is the null result of sensitive scanning magnetometry experiments designed to detect the expected spontaneous charge currents. Motivated by junction tunneling conductance measurements, which indicate the quenching of superconductivity at the surfaces of even high-purity samples, we examine the spontaneous currents in a chiral …