Year: 2017
Type: article
Abstract: We investigate the proximity effect in InAs nanowire (NW) junctions with superconducting contacts made of Al. The carrier density in InAs is tuned by means of the back gate voltage V g . At high positive V g the devices feature transport signatures characteristic of diffusive junctions with highly transparent interfaces—sizable excess current, re-entrant resistance effect and proximity gap values ( Δ N ) close to the Al gap ( Δ 0 ). At decreasing V g , we observe a reduction of the proximity gap down to Δ N ≈ Δ 0 / 2 at NW conductances ∼ 2 e 2 h − 1 , which is interpreted in terms of carrier density dependent reduction of the Al/InAs interface transparency. We demonstrate that the experimental behavior of Δ N is closely reproduced by a model with rectangular potential barrier at the Al/InAs interface.
Authors: A V Bubis, A O Denisov, S U Piatrusha, I E Batov, V S Khrapai, J Becker, J Treu, D Ruhstorfer, G Koblmüller
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W2611530801