Fluxon Dynamics in Three Stacked Josephson Junctions
Carlos Gorria
University of the Basque Country. Bilbao, Spain
Abstract:
In this work it is presented a system of 3 stacked Josephson-junctions
described by a set of 3 coupled sine-Gordon equations. It is shown
there are qualitative differences with the well established case of 2
junctions. These nonlinear equations are not Lorenz invariant. We have
solved numerically the fully nonlinear equations for different
distribution of travelling-wave solutions and we prove the
fluxon-antifluxon-fluxon initial condition is the only stable
configuration which does not radiate significantly. The interaction
produces an "overshoot" in the shape of the antifluxon and its height
depends on its velocity and the coupling constant. We obtain analytical
solution of the piece-wise linearized equations and it agrees well with
the numerical solution of fully nonlinear system when the velocity is
small.