Switching noise in YBa/sub 2/Cu/sub 3/O/sub x/ 'macrobridges'

Intermittent switching was observed in the voltage current characteristics of thin-film bridges of YBa/sub 2/Cu/sub 3/O/sub x/. At a fixed bias point there are multiple metastable voltage states with lifetimes which depend on the bias current and applied magnetic field. The microbridges are made of thin (<500 nm) polycrystalline films of YBa/sub 2/Cu/sub 3/O/sub x/ which are patterned by liftoff into structures with dimensions ranging from less than 1 mu m. to 100 mu m. Details of the fabrication process and the measurements are presented. The results are discussed in the context of fluctuations in the effective resistance of the bridge due to motion of trapped flux.<
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