Microwave and dc response of an Abrikosov vortex lattice in ferromagnetic superconductors

In magnetic superconductors the magnetic flux dynamics is influenced by the interaction of vortices with the magnetization. This interaction leads to the appearance of an additional damping force acting on the vortices. By solving the London and Landau-Lifshitz-Gilbert equations we analyze the ac and dc responses of a ferromagnetic superconductor in the mixed state. If the vortices are driven by an ac force, their viscosity is enhanced due to the generation of magnons. This viscosity enhancement affects the surface impedance of the sample. In the case of a dc driving current vortices start to radiate magnons when their velocity exceeds a threshold value. As a result, either a step-like feature or a series of peaks appear on the I-V curve.Des nanosondes ultra-sensibles pour explorer les distributions de charges électriques dans les supraconducteursNew Century of Superconductivity: Ideas, Materials, Technologie