Size Dependence of Individual Vortex Penetration into Intrinsic Josephson Junction Stacks of Bi2Sr2CaCu2O8+y

By c-axis transport measurements in an intrinsic Josephson junctions (IJJs) stack of Bi2Sr2CaCu2O8+y in magnetic fields parallel to c-axis, a penetration of individual vortices can be detected as a sudden jump or drop of c-axis resistance or critical current, which has already been reported in a sample of small in-plane area (<2 μm2). We explored the individual vortex penetrations in IJJs stacks with much larger in-plane areas and successfully observed the same phenomenon even in a sample as large as 100 μm2. Behavior of the c-axis resistance and critical current caused by the individual vortex penetrations are investigated through the sample-size dependence in various temperatures and magnetic fields.