Parametric mixing in a nonlinear TlCaBaCuO thin film resonator at microwave frequencies

The RF nonlinear behavior of a TlCaBaCuO thin film at 77 K is investigated. The film is patterned to form a disk with small annular perforations along the outer edge, and a dielectric resonator is used to couple to the structure. Thinning of the film with a bromine etch greatly enhances the reactive nonlinearity of the resonator structure. Scalar network analyzer measurements revealed sufficient nonlinearity to achieve parametric amplification at 7.2 GHz. The nonlinearity is tentatively attributed to RF-induced flux in the superconducting film.