Polariton-like interaction between microwaves and electronic subsystem of metal oxide superconductor

In studying the microwave (10 GHz) response of both single crystal and ceramic samples of the YBa 2Cu 3O 7 in Nb resonator we have found dielectric permittivity dependent strongly on wave-vector resulting in appearance of the new dielectric resonances with hysteretic temperature behaviour. Data show the importance of the non-conducting “bound” electron polarization in strong local fields and spatial dispersion, which lead to the polariton-like interaction between microwaves and electrons in a high-T c superconductor. The effects of the polariton-like microwave excitations on the limiting mechanisms in superconducting cavities are discussed.