Non-equilibrium microwave response of YBa 2 Cu 3 O 7-δ granular thin films under magnetic fields

Microwave responses of YBa 2 Cu 3 O 7-δ (YBCO) granular film have been studied at the microwave frequency of 30.5 GHz. In the absence of a magnetic field the dependence of a normal microwave response on the bias current is observed at a temperature close to T c . When a magnetic field ranged from 5.0 mT to 33.0 mT is applied, the responses broaden and shift toward a lower temperature. In the superconducting state, the responses were found to be highly dependent on the magnetic field. For the current equal to 5.0 mA and a magnetic field above 17.0 mT the response increases and did not vanish even at a very low temperature, the fact is believed to be correlated to the anisotropic character of the structure.