  Arrays of dopants in silicon are promising platforms for the quantum
simulation of the Fermi-Hubbard model. We show that the simplest model with
only on-site interaction is insufficient to describe the physics of an array of
phosphorous donors in silicon due to the strong intersite interaction in the
system. We also study the resonant tunneling transport in the array at low
temperature as a mean of probing the features of the Hubbard physics, such as
the Hubbard bands and the Mott gap. Two mechanisms of localization which
suppresses transport in the array are investigated: The first arises from the
electron-ion core attraction and is significant at low filling; the second is
due to the sharp oscillation in the tunnel coupling caused by the intervalley
interference of the donor electron's wavefunction. This disorder in the tunnel
coupling leads to a steep exponential decay of conductance with channel length
in one-dimensional arrays, but its effect is less prominent in two-dimensional
ones. Hence, it is possible to observe resonant tunneling transport in a
relatively large array in two dimensions.
