Abstract
Graham Kells (Freie Universität Berlin, Germany)
Sub-gaps in multi-channel Majorana wires and a nucleated Z2 index
We study the structure of Majorana end states together with their associated sub-gap states in a p+ip superconductor placed in a narrow strip geometry. We present two simple models, focusing on the low energy states bounded to the short and long sides of the strip, that allow us to analytically study the dependence of the excitation gap on the width of the sample relative to the superconducting coherence length. Both models also provide intuitive explanations for the series of topological phase transitions that occur as the system parameters are varied.