Edge-mode Superconductivity in a Two Dimensional Topological Insulator

Abstract

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.

19 pages, 17 figures

References in corpus (12)

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• Quantum Spin Hall Insulator State in HgTe Quantum Wells
• Signatures of Majorana fermions in hybrid superconductor-semiconductor nanowire devices
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• Tunable Supercurrent Through Semiconductor Nanowires
• Evidence for crossed Andreev reflection in superconductor-ferromagnet hybrid structures
• Fermion-parity anomaly of the critical supercurrent in the quantum spin-Hall effect
• Spin-triplet supercurrent carried by quantum Hall edge states through a Josephson junction
• Proximity-induced superconductivity and Josephson critical current in quantum spin Hall systems

Cited by in corpus (17)

• Strong localization of Majorana end states in chains of magnetic adatoms
• A road to reality with topological superconductors
• Odd-frequency superconducting pairing and subgap density of states at the edge of a two-dimensional topological insulator without magnetism
• Anomalous Fraunhofer Interference in Epitaxial Superconductor-Semiconductor Josephson Junctions
• Conventional Superconductivity in Type II Dirac Semimetal PdTe${}_2$
• High efficiency thermal switch based on topological Josephson junctions
• Edge transport in InAs and InAs/GaSb quantum wells
• $h/e$ superconducting quantum interference through trivial edge states in InAs
• Detecting topological superconductivity using low-frequency doubled Shapiro steps
• Single-edge transport in an InAs/GaSb quantum spin Hall insulator
• Engineering quantum spin Hall insulators by strained-layer heterostructures
• Multiple odd-frequency superconducting states in buckled quantum spin Hall insulators with time-reversal symmetry
• Proximity-induced superconductivity within the InAs/GaSb edge conducting state
• Identify the topological superconducting order in a multi-band quantum wire
• Edge absorption and pure spin current in 2D topological insulator in the Volkov-Pankratov model
• Critical Current Anomaly at the Topological Quantum Phase Transition in a Majorana Josephson Junction
• Interaction effects in superconductor/quantum spin Hall devices: universal transport signatures and fractional Coulomb blockade