Localized rotating-modes in capacitively coupled intrinsic Josephson junctions: Systematic study of branching structure and collective dynamical instability

摘要

A variety of the Ⅰ-Ⅴ characteristics observed in a stack of intrinsic Josephson junctions is systematically explained in terms of the dynamics of the localized rotating mode in the discrete nonlinear systems. We clarify the effect of the capacitive coupling constant on the Ⅰ-Ⅴ characteristics, using the capacitively coupled Josephson junction model. The branch structure in the Ⅰ-Ⅴ characteristics changes from an assembly of equi-distance branches to a single hysteresis-loop-like structure as the capacitive coupling constant increases. This behavior is in accordance with experiments. We predict that dynamical transitions between collective rotating states take place in the resistive state of a stack of intrinsic Josephson junctions in the strong capacitive coupling regime. These transitions create step-like structure in the Ⅰ-Ⅴ characteristics, which is observed in La_(1-x)Sr_xCuO_(4-δ).