Dynamics of point Josephson junctions in a microstrip line

Abstract

We model the dynamics of point Josephson junctions in a 1D microstrip line using a wave equation with delta distributed sine nonlinearities. The model is suitable for both low T$_c$ and high T$_c$ systems (0 and $\pi$ junctions). For a single junction in the line, we found two limiting behaviors: the ohmic mode where the junction acts as a pure resistor which stops waves and separates the cavity and the junction mode where the wave is homogeneous throughout the strip. This classification allows to bound the IV curves of the system. Two junctions in a strip give generally ohmic modes and combined junction/ohmic modes and yield information about the behavior with an array with many junctions. Finally we use this analysis to understand the many junction case for 0 and $\pi$ junctions and the effect of an external magnetic field.