Quantum oscillation of the c-axis resistivity due to entrance of pancake vortices into micro-fabricated Bi2Sr2CaCu2O8+δ intrinsic Josephson junctions

The c-axis resistance in Bi2Sr2CaCu2O8+δ intrinsic Josephson junctions (IJJs) with areas of the ab-plane less than 2 μm2 were measured as functions of applied magnetic field and angle to the crystalline axes. When the magnetic field is tilted off from the lock-in state of Josephson vortices, several sharp dips are found. The separation between the dips approaches to the value corresponding to ϕ0 with further tilting the external magnetic field. This behavior is attributed to the penetration of a quantized pancake vortex into the tiny IJJ. This argument is further supported by the result that the c-axis resistance under magnetic fields parallel to the c-axis shows identical stepwise behavior.