Observation of edge transport in the disordered regime of topologically insulating InAs / GaSb quantum wells

Abstract

We observe edge transport in the topologically insulating InAs/GaSb system in the disordered regime. Using asymmetric current paths we show that conduction occurs exclusively along the device edge, exhibiting a large Hall signal at zero magnetic fields, while for symmetric current paths, the conductance between the two mesoscopicly separated probes is quantized to 2e2/h. Both quantized and self-averaged transport show resilience to magnetic fields, and are temperature independent for temperatures between 20 mK and 1 K. © 2014 American Physical Society.