  Despite the importance of Si:P delta-doped wires for modern nanoelectronics,
there are currently no computational models of electron transport in these
devices. In this paper we present a nonequilibrium Green's function model for
electronic transport in a delta-doped wire, which is described by a
tight-binding Hamiltonian matrix within a single-band effective-mass
approximation. We use this transport model to calculate the current-voltage
characteristics of a number of delta-doped wires, achieving good agreement with
experiment. To motivate our transport model we have performed
density-functional calculations for a variety of delta-doped wires, each with
different donor configurations. These calculations also allow us to accurately
define the electronic extent of a delta-doped wire, which we find to be at
least 4.6 nm.
