Abstract
We experimentally investigate Andreev transport through the interface between an indium superconductor and the edge of the InAs/GaSb bilayer. To cover all possible regimes of the InAs/GaSb spectrum, we study samples with 10-nm-, 12-nm-, and 14-nm-thick InAs quantum wells. For the trivial case of a direct band insulator in 10 nm samples, differential resistance demonstrates standard Andreev reflection. For InAs/GaSb structures with band inversion (12 and 14 nm samples), we observe distinct low-energy structures, which we regard as direct evidence for the proximity-induced superconductivity within the current-carrying edge state. For 14 nm InAs well samples, we additionally observe mesoscopiclike resistance fluctuations, which are subjected to threshold suppression in low magnetic fields.
- Received 19 July 2017
DOI:https://doi.org/10.1103/PhysRevB.96.245304
©2017 American Physical Society