High-field Josephson magnetic resonance in high-temperature superconductors

The possibility of high-field Josephson magnetic resonance (HFJMR) in high-temperature superconductors (HTSCs) is theoretically demonstrated. The HFJMR mechanism is related to the Josephson oscillations in intergranular junctions of a polycrystalline HTSC, which are caused by the penetration of Abrikosov vortices into the grains. In fields within H-c1 <= H < H-x (where H-c1 is the first critical field and H-x is the field corresponding to vortex separation from pinning centers in the grains), measurements of the microwave absorption spectra of a sample can be used for investigations of the HTSC macrostructure and the properties of vortex matter. In the latter aspect, the HFJMR method is analogous to the SQUID technique.