On the dynamics of Josephson-junction circuits

A qualitative theory of the circuit dynamics of the Josephson-junction device using a simple circuit model is developed. By examining trajectories on a cylindrical phase space and on the surface of a torus, respectively, the main features of thel/V characteristics of the junction excited by D.C. and a.c. are explained, and their properties derived. These results lead to the interpretation of the steps of constant voltage in the a.c. characteristics as a manifestation of the synchronisation phenomenon