We theoretically consider the proximity effect in semiconductor-superconductor hybrid nanostructures, which are being extensively studied in the context of the ongoing search for non-Abelian Majorana fermions in solid state systems. Specifically, we consider the dependence on the thickness of the semiconductor in the direction normal to the interface, a physical effect that has been uncritically neglected in all prior work on the subject. Quite surprisingly, we find the completely unanticipated result that increasing the semiconductor thickness leads to a drastic suppression of the induced superconducting gap due to proximity-induced interband coupling. As a result, in the limit of strong semiconductor-superconductor coupling, the proximity-induced gap becomes much smaller than the bulk superconductor gap and depends weakly on the interface transparency.
Digital Commons Citation
Stanescu, Tudor D. and Das Sarma, S., "Superconducting proximity effect in semiconductor nanowires" (2013). Faculty & Staff Scholarship. 355.
Stanescu, Tudor D., &Das Sarma, S. (2013). Superconducting Proximity Effect In Semiconductor Nanowires. Physical Review B - Condensed Matter and Materials Physics, 87(18). http://doi.org/10.1103/PhysRevB.87.180504