The Josephson current between an s-wave and a spin-triplet superconductor ${\mathrm{Sr}}_2{\mathrm{RuO}}_4$ (SRO) is studied theoretically. In spin-singlet/spin-triplet superconductor junctions, there is no Josephson current proportional to $\sin \phi$ in the absence of the spin-flip scattering near junction interfaces, where $\phi$ is a phase difference across junctions. Thus, a dominant term of the Josephson current is proportional to $\sin 2\phi .$ The spin-orbit scattering at the interfaces gives rise to the Josephson current proportional to $\cos \phi ,$ which is a direct consequence of the chiral paring symmetry in SRO.

• Received 10 December 2002

DOI:https://doi.org/10.1103/PhysRevB.67.184505