We study the spin and vortex dynamics in the spontaneous vortex phase of magnetic superconductors. Equations of motion are derived which incorporate the coupling between the superconducting and magnetic components, as well as coupling between spin and vortex motion. We show that coupling between the spin and vortex degrees of freedom leads to new dynamical phenomena in the spontaneous vortex phase. In particular spin waves develop a minimum at wave vectors of the spiral instability in some directions and the electromagnetic waves propagate through the superconductor due to coupling to spin waves in some directions. These can be studied by inelastic neutron scattering and microwave experiments respectively.

• Received 4 March 1998

DOI:https://doi.org/10.1103/PhysRevB.58.11624