Charge to Fermion fractionalization crossover in a topological superconductor device

Topological insulators and topological superconductors allow for fractionalized excitations, which can be utilized for quantum computation. First of these is a fractionalized charge excitation where a charge e/4 is bound to a magnetic vortex due to the Witten effect. The second one is a charge neutral excitation composed of two Majorana zero modes. There are now experimental setups available to realize these excitations in solid state electronic devices. In this project we will explore how these two exotic excitations are related and study how one might evolve into the other, and discover  whether there is a crossover or a quantum phase transition along that evolution.