Spin and Spin-Wave Dynamics in Josephson Junctions

We explore the dynamics of a single spin and spin wave dynamics of ferromagnets when these are inserted between superconducting leads. Several new effects are reported. Chief amongst these are new nutations of single $s=\raise0.7ex\hbox{$1$} \!\mathord{\left/ {\vphantom {1 2}}\right.\kern-\nulldelimiterspace}\!\lower0.7ex\hbox{$2$}$ spins in Josephson junctions. These nutations are sparked by the superconducting pairing correlations. Similarly, we find that on rather universal grounds, magnets display unconventional spin wave dynamics when placed in Josephson junctions. These lead to modifications in the tunneling current.