Edge transport in the trivial phase of InAs/GaSb

Edge transport in the trivial phase of InAs/GaSb

Nichele, Fabrizio (University of Copenhagen)
Suominen, Henri J. (University of Copenhagen)
Kjaergaard, Morten (University of Copenhagen)
Marcus, Charles M. (University of Copenhagen)
Sajadi, Ebrahim (University of British Columbia)
Folk, Joshua A. (University of British Columbia)
Qu, F. (TU Delft QRD/Kouwenhoven Lab)
Beukman, A.J.A. (TU Delft QRD/Kouwenhoven Lab)
de Vries, F.K. (TU Delft QRD/Kouwenhoven Lab)
van Veen, J. (TU Delft QRD/Kouwenhoven Lab)
Nadj-Perge, S. (TU Delft QN/Quantum Transport)
Kouwenhoven, Leo P. (TU Delft QRD/Kouwenhoven Lab)

2016

We present transport and scanning SQUID measurements on InAs/GaSb double quantum wells, a system predicted to be a two-dimensional topological insulator. Top and back gates allow independent control of density and band offset, allowing tuning from the trivial to the topological regime. In the trivial regime, bulk conductivity is quenched but transport persists along the edges, superficially resembling the predicted helical edge-channels in the topological regime. We characterize edge conduction in the trivial regime in a wide variety of sample geometries and measurement configurations, as a function of temperature, magnetic field, and edge length. Despite similarities to studies claiming measurements of helical edge channels, our characterization points to a non-topological origin for these observations.

INAS/GASB
Quantum spin Hall effect
Scanning SQUID
Topological insulator

http://resolver.tudelft.nl/uuid:bee065eb-7b86-443d-93e0-e19f2800fa3e

https://doi.org/10.1088/1367-2630/18/8/083005

1367-2630

New Journal of Physics, 18 (8)

Institutional Repository

journal article

© 2016 Fabrizio Nichele, Henri J. Suominen, Morten Kjaergaard, Charles M. Marcus, Ebrahim Sajadi, Joshua A. Folk, F. Qu, A.J.A. Beukman, F.K. de Vries, J. van Veen, S. Nadj-Perge, Leo P. Kouwenhoven, More Authors