High-mobility InAs two dimensional electron systems on GaSb substrates

The two dimensional electron gas in InAs quantum wells grown on nearly lattice-matched GaSb substrates is an attractive stage for mesoscopic device physics. However, use of this system has remained difficult due to outstanding challenges. Here we report on heterostructure design optimization and device fabrication that satisfies three main criteria for mesoscopic device operation: electrical isolation from the semiconducting substrate, ability to fully deplete the charge carriers and control residual sidewall conduction with lithographic gates, and high mobility to ensure ballistic transport over mesoscopic length scales [1]. In addition, we discuss our current progress in realization of mesoscopic devices including quantum point contacts and quantum dots.

[1] C. Thomas, A. T. Hatke, A. Tuaz, R. Kallaher, T. Wu, T. Wang, R. E. Diaz, G. C. Gardner, M. A. Capano, and M. J. Manfra, Phys. Rev. Mat. 2, 104602 (2018).