Charge and Spin Manipulation in InAs Nanowires

Abstract

This thesis presents a series of experiments concerning electrons confined in InAs nanowires, which are quasi-one dimensional semiconductor systems. InAs is an interesting material for a variety of reasons, many of which involve its excellent electronic properties, but this thesis focuses on the effects of its strong spin-orbit coupling. We have developed protocols for the growth of these nanowires with very low densities of defects, which allow the formation of few electron double quantum dots. By accessing a two electron charge state, electron transport through the nanowire becomes sensitive to the internal spin state of the quantum dot. We use this `spin to charge conversion' to measure single spin resonance, which we drive through the spin-orbit coupling. In addition to allowing rapid spin manipulation, the strong spin-orbit strength of InAs produces novel behavior, including large anisotropy and tunability of the g-tensor, and apparent multiple photon absorption of an applied microwave field. Finally, by coupling a resonator to the nanowire, we have demonstrated a form of charge sensing which is directly sensitive to the spin state of the double quantum dot.