We theoretically investigate cross-talk in hyperfine gate control of donor-qubit quantum computer architectures, in particular the Kane proposal. By numerically solving the Poisson and Schr\"{o}dinger equations for the gated donor system, we calculate the change in hyperfine coupling and thus the error in spin-rotation for the donor nuclear-electron spin system, as the gate-donor distance is varied. We thus determine the effect of cross-talk - the inadvertent effect on non-target neighbouring qubits - which occurs due to closeness of the control gates (20-30nm). The use of compensation protocols is investigated, whereby the extent of crosstalk is limited by the application of compensation bias to a series of gates. In light of these factors the architectural implications are then considered.
@article{arxiv.cond-mat/0605081,
title = {Cross-talk compensation of hyperfine control in donor qubit architectures},
author = {G Kandasamy and C J Wellard and L C L Hollenberg},
journal= {arXiv preprint arXiv:cond-mat/0605081},
year = {2009}
}