Josephson Effect between Noncentrosymmetric LaPt3Si and a Conventional Superconductor

The Josephson effect between LaPt 3 Si and Al has been investigated for junctions on the (100) and (001) faces of LaPt 3 Si single crystals and a polycrystal. In the magnetic-field dependence of the Josephson critical current, the anomaly previously reported for CePt 3 Si appeared; an oscillating pattern without a dominant maximum peak at zero field was observed for the junction on the (001) face. This cannot be interpreted as the Josephson effect between conventional s -wave superconductors and suggests that the origin of the anomaly lies in the noncentrosymmetric crystal structure.