Topological superconductivity is an exotic state of matter that supports Majorana zero-modes, which are surface modes in 3D, edge modes in 2D or localized end states in 1D. In the case of complete localization these Majorana modes obey non-Abelian exchange statistics making them interesting building blocks for topological quantum computing. Here we report superconductivity induced into the edge modes of semiconducting InAs/GaSb quantum wells, a two-dimensional topological insulator. Using superconducting quantum interference, we demonstrate gate-tuning between edge-dominated and bulk-dominated regimes of superconducting transport. The edge-dominated regime arises only under conditions of high-bulk resistivity, which we associate with the 2D topological phase. These experiments establish InAs/GaSb as a robust platform for further confinement of Majoranas into localized states enabling future investigations of non-Abelian statistics.
@article{arxiv.1408.1701,
title = {Edge-mode Superconductivity in a Two Dimensional Topological Insulator},
author = {Vlad S. Pribiag and Arjan J. A. Beukman and Fanming Qu and Maja C. Cassidy and Christophe Charpentier and Werner Wegscheider and Leo P. Kouwenhoven},
journal= {arXiv preprint arXiv:1408.1701},
year = {2015}
}