Supercurrent peaks in planar high-temperature superconducting Josephson junctions

We investigate the current-voltage (IV) characteristics of planar high-temp erature superconducting Josephson junctions in the physically relevant over damped limit. We show that the nonuniform bias current distribution induced by the planar geometry leads to unexpected modifications of the IV charact eristic, including a resonancelike supercurrent peak that moves with applie d magnetic field. We show that these are not resonance effects, but are due to a dynamical instability in the supercurrent distribution. All of the se veral bias distributions investigated result in the field-dependent supercu rrent peaks.