2019/08/23 by Pauka, S. J., Witt, J. D. S., Allen, C. N. +9 · 1 citation
#FOS: Physical sciences #Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
paper · doi:10.48550/arxiv.1908.08689
Candidate systems for topologically-protected qubits include two-dimensional electron gases (2DEGs) based on heterostructures exhibiting a strong spin-orbit interaction (SOI) and superconductivity via the proximity effect. For InAs- or InSb-based materials, the need to form shallow quantum wells to create a hard-gapped p-wave superconducting state often subjects them to fabrication-induced damage, limiting their mobility. Here we examine scattering mechanisms in processed InAs 2DEG quantum wells and demonstrate a means of increasing their mobility via repairing the semiconductor-dielectric interface. Passivation of charged impurity states with an argon-hydrogen plasma results in a significant increase in the measured mobility and reduction in its variance relative to untreated samples, up to 45300 cm2/(V s) in a 10 nm deep quantum well.