Properties of superconductor-antiferromagnet-superconductor Josephson junctions in SO(5) theory

We derive the qualitative behavior of superconductor-antiferromagnet-superconductor (SAS) Josephson junctions described by Zhang’s SO(5) theory. The main differences between these junctions and conventional superconductor-insulator-superconductor junctions arise from the nonsinusoidal current-phase relation derived by Demler et al. for thin SAS junctions. Using a simple approximation to this nonsinusoidal function, the current voltage relation, Shapiro steps, thermal fluctuation effects, and the diffraction pattern in a magnetic field are obtained.