title: Edge-mode superconductivity in a two-dimensional topological insulator.
abstract: Topological superconductivity is an exotic state of matter that supports Majorana zero-modes, which have been predicted to occur in the surface states of three-dimensional systems, in the edge states of two-dimensional systems, and in one-dimensional wires. Localized Majorana zero-modes obey non-Abelian exchange statistics, making them interesting building blocks for topological quantum computing. Here, we report superconductivity induced in 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 two-dimensional topological phase. These experiments establish InAs/GaSb as a promising platform for the confinement of Majoranas into localized states, enabling future investigations of non-Abelian statistics.
authors.affiliation: Kavli Institute of Nanoscience, Delft University of Technology, Delft, GA 2600, The Netherlands.
authors.forename: Vlad S
authors.initials: VS
authors.lastname: Pribiag
authors.affiliation: Kavli Institute of Nanoscience, Delft University of Technology, Delft, GA 2600, The Netherlands.
authors.forename: Arjan J A
authors.initials: AJ
authors.lastname: Beukman
authors.affiliation: Kavli Institute of Nanoscience, Delft University of Technology, Delft, GA 2600, The Netherlands.
authors.forename: Fanming
authors.initials: F
authors.lastname: Qu
authors.affiliation: Kavli Institute of Nanoscience, Delft University of Technology, Delft, GA 2600, The Netherlands.
authors.forename: Maja C
authors.initials: MC
authors.lastname: Cassidy
authors.affiliation: Solid State Physics Laboratory, ETH Zürich, Zürich 8093, Switzerland.
authors.forename: Christophe
authors.initials: C
authors.lastname: Charpentier
authors.affiliation: Solid State Physics Laboratory, ETH Zürich, Zürich 8093, Switzerland.
authors.forename: Werner
authors.initials: W
authors.lastname: Wegscheider
authors.affiliation: Kavli Institute of Nanoscience, Delft University of Technology, Delft, GA 2600, The Netherlands.
authors.forename: Leo P
authors.initials: LP
authors.lastname: Kouwenhoven