Edge transport in InAs and InAs/GaSb quantum wells

Susanne Mueller, Christopher Mittag, Thomas Tschirky, Christophe Charpentier, Werner Wegscheider, Klaus Ensslin, Thomas Ihn

Published 2017-06-01Version 1

We investigate low-temperature transport through single InAs quantum wells and broken-gap InAs/GaSb double quantum wells. Non-local measurements in the regime beyond bulk pinch-off confirm the presence of edge conduction in InAs quantum wells. The edge resistivity of 1-2 $\mathrm{k\Omega/\mu m}$ is of the same order of magnitude as edge resistivities measured in the InAs/GaSb double quantum well system. Measurements in tilted magnetic field suggests an anisotropy of the conducting regions at the edges with a larger extent in the plane of the sample than normal to it. Finger gate samples on both material systems shine light on the length dependence of the edge resistance with the intent to unravel the nature of edge conduction in InAs/GaSb coupled quantum wells.