Periodic and non-periodic current steps in I–V characteristics in mesoscopic intrinsic Josephson junctions of Bi2212

We have studied the dynamical nature of Josephson vortices in an intrinsic Josephson junction by current–voltage characteristics measurements along the c-axis of the mesoscopic Bi2Sr2CaCu2O8+δ single crystals. We found periodic and non-periodic current steps with respect to the voltage. The former resembles the Fiske resonance observed in a single junction and the latter is considered to be peculiar to intrinsic Josephson junctions.