Simulation of the Effect of Temperature on Flux-Flow Behavior in Stacked Intrinsic Josephson Junctions

Abstract

We have numerically studied the effect of temperature on the flux-flow behavior in a stack of intrinsic Josephson junctions by using the inductive coupling Josephson junctions model taking into account thermal fluctuations. In the absence of noise, the current-voltage characteristic shows a series of clear Fiske and flux-flow steps depending on an external magnetic field. With increasing temperature the Fiske steps corresponding to the out-of-phase mode remain on the current-voltage characteristic but other steps disappear. This suggests that the out-of-phase cavity mode becomes more stable than other modes due to the fluctuations. Furthermore, it is found that the in-phase flux flow mode is also strongly affected by the thermal noise in contrast to the out-of-phase one and fluctuations disturb the formation of the rectangular lattice of vortices even in the flux-flow mode driven by a strong Lorentz force Our results can qualitatively explain recent experimental observations in intrinsic Josephson junctions in the flux-flow state.