%0 Journal Article
%T Effects of J-gate potential and interfaces on donor exchange coupling in the Kane quantum computer architecture
%A L. M. Kettle
%A H. -S. Goan
%A Sean C. Smith
%A L. C. L. Hollenberg
%A C. J. Wellard
%J Physics
%D 2004
%I arXiv
%R 10.1088/0953-8984/16/7/001
%X We calculate the electron exchange coupling for a phosphorus donor pair in silicon perturbed by a J-gate potential and the boundary effects of the silicon host geometry. In addition to the electron-electron exchange interaction we also calculate the contact hyperfine interaction between the donor nucleus and electron as a function of the varying experimental conditions. Donor separation, depth of the P nuclei below the silicon oxide layer and J-gate voltage become decisive factors in determining the strength of both the exchange coupling and the hyperfine interaction - both crucial components for qubit operations in the Kane quantum computer. These calculations were performed using an anisotropic effective-mass Hamiltonian approach. The behaviour of the donor exchange coupling as a function of the device parameters varied provides relevant information for the experimental design of these devices.
%U http://arxiv.org/abs/cond-mat/0402183v1