Modelling single electron transfer in Si:P double quantum dots

Solid-state systems such as P donors in Si have considerable potential for the realization of scalable quantum computation. Recent experimental work in this area has focused on implanted Si:P double quantum dots (DQDs) that represent a preliminary step towards the realization of single donor charge-based qubits. This paper focuses on the techniques involved in analysing the charge transfer within such DQD devices and understanding the impact of fabrication parameters on this process. We show that misalignment between the buried dots and surface gates affects the charge transfer behaviour, and identify some of the challenges posed by reducing the size of the metallic dot to the few donor regime.