Study of Surface Quantum Wells in InSb/AlInSb Heterostructures

Abstract

The strong spin orbit coupling and large Lande g-factor of InSb compared to the other III-V semiconductors makes InSb an ideal choice for potential use in topological quantum computing with Majorana fermions. Furthermore, two dimensional electron gases (2DEGs) in III-V materials offer a more scalable platform for topological quantum computing over nanowire networks. Despite their ideal properties, 2DEGs in InSb have not been exploited for the purpose of studying Majorana fermions due to outstanding materials development challenges. This thesis presents an investigation of InSb/AlInSb heterostructures including surface quantum wells and standard high electron mobility transistor (HEMT) heterostructures. Development of fabrication methods and techniques is discussed for each system. Transport is characterized through mangetotransport measurements including quantum Hall effect and Shubnikov de-Haas oscillations. We extract carrier densities and mobilities for a series of wafers of varying doping densities. Gated structures allow further modulation of the carrier density and characterization of the effectiveness of gating is reported.