Majorana Zero Modes and Braiding in Realistic Nanowire Y-Junctions

Under the right conditions, semiconductor nanowires are believed to host zero-energy Majorana fermions, particles with non-abelian properties suitable for topological quantum computation. While recent experiments have demonstrated encouraging local signatures of Majorana fermions, evidence for their non-abelian nature remains elusive. Motivated by ongoing experimental work at IBM, we build a realistic model of a nanowire Y-junction and study the properties of the resulting Majorana fermions numerically. We make quantitative predictions about the device parameters and geometry that are conducive to realising Majorana zero modes, and study the corresponding experimental signatures that would be expected. We go on to simulate braiding operations between multiple Majorana fermions, and suggest experimental gating protocols that may lead to signatures of their non-abelian nature.