ABSTRACT
Due to the rapidly shrinking device sizes, modern-day metal-oxide-
semiconductor field-effect transistors (MOSFETs) already have a few
discrete dopants governing the current-voltage characteristics in
the subthreshold regime [21]. Besides their role in conventional
electronics, dopants are also finding their use in novel quantum
technology. A single phosphorus donor in silicon has been proposed
as the building block of a scalable quantum computer compatible
with the current processing infrastructure of the semiconductor
industry [10]. Arrays of donors patterned by scanning tunneling
microscopes [27] have already been used to make some of the
smallest devices ever developed, such as the world’s thinnest
nanowire [32] and the smallest transistors [7]. To understand all
these donor-based quantum devices under a unified framework, we
need to understand how the donor electron responds to external
electric fields from nearby electrodes.
