Nonlinear response of suspended high temperature superconducting thin film microwave resonators

The nonlinear microwave surface impedance, Z/sub s/(H/sub rf/) of Y/sub 1/Ba/sub 2/Cu/sub 3/O/sub 7/(-/spl delta/) thin films is measured using suspended patterned resonators. We find that the nonlinear response is well described in terms of a single mechanism, namely the hysteretic ac response of the current-induced critical state.<
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