New type of zero-field steps in the I-V curve of a Josephson junction of intermediate length

We report on the observation of a new type of high-order zero-field steps in the I-V curve of a Josephson transmission line of intermediate length l = L/lambda/sub J/roughly-equal5, where lambda/sub J/ is the Josephson penetration length. On such steps, deviations from the generalized Josephson relation V/sub dc/ = N(h/2e)ν/sub det/ relating the measured dc voltage to the frequency of the radiation emitted from the junction are observed