We have measured the magnetic field dependence of the supercurrent in micron‐size medium and high current density superconducting‐normal‐superconducting Nb–Au–Nb Josephson junctions. We find good quantitative agreement between the experiment and a theory for the distributed Josephson effect in such junctions. For finite bias voltages, high current density junctions show a monotonic decrease in the effective critical current with increasing field in sharp contrast to the resistively shunted junction model which predicts the well‐known Fresnel‐type behavior. Our medium current density junctions represent an intermediate case, residual Fresnel behavior is observed at small bias voltages, but a monotonic decrease with the field is observed for higher bias voltages.
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