A study of fluxons propagating in annular josephson junctions

In this research we looked at how fluxons propagate in an annular Josephson junction containing a microshort. We studied this from a theoretical stance and looked at how a single fluxon based on the sine-Grodon soliton equation propagates in this type of junction. It has been seen from a variety of studies that fluxons have many applications through the use of Josephson junctions. The aim of this thesis was to see whether a fluxon will show new properties whilst coming into contact with a microshort located in the junction. We also explored the different geometries a Josephson junction can have and whether that would show the fluxon to present new phenomena. We will also examine point particle systems. With this in mind we took a keen interest in how the interaction between two of these particles in a double well potential would present itself and whether a relationship would become apparent. Alongside the point particle system we modelled fluxons in a double well potential and comment on the similarities with the point particle system. With the aid of the computer programmes Mathematica and COMSOL Multiphysics we were able to compute these different theoretical models and present the work in a logical order with a progression from a single point particle in a double well potential to a fluxon in a heart-shaped Josephson junction. We have looked at current theories and ideas present in this area of condensed matter physics and have explained these in the subsequent thesis.