Nonlinear oscillations produced in complex Josephson circuits

A description is presented of the chaotic phenomena and its associated oscillations produced in superconducting circuits with two types of Josephson junctions, one is a tunnel-type and the other is a bridge-type. The results of analysis show the chaotic oscillations in the circuit with a bridge-type Junction can be observed in a special case. Furthermore, a forced oscillation circuit with two Josephson junctions in series connection has been investigated. The simulation results show a new oscillation mode which is something like white noise. Emphasis is placed on the study of the difference of oscillation modes produced in the circuit with a tunnel-type junction and a bridge-type junction.<>