We investigate zero-bias conductance peaks that arise from coalescing subgap Andreev states, consistent with emerging Majorana zero modes, in hybrid semiconductor-superconductor wires defined in a two-dimensional InAs/Al heterostructure using top-down lithography and gating. The measurements indicate a hard superconducting gap, ballistic tunneling contact, and in-plane critical fields up to 3~T. Top-down lithography allows complex geometries, branched structures, and straightforward scaling to multicomponent devices compared to structures made from assembled nanowires.
@article{arxiv.1703.03699,
title = {Zero-Energy Modes from Coalescing Andreev States in a Two-Dimensional Semiconductor-Superconductor Hybrid Platform},
author = {Henri J. Suominen and Morten Kjaergaard and Alexander R. Hamilton and Javad Shabani and Chris J. Palmstrøm and Charles M. Marcus and Fabrizio Nichele},
journal= {arXiv preprint arXiv:1703.03699},
year = {2017}
}