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Effects of J-gate potential and interfaces on donor exchange coupling in the Kane quantum computer architecture

L. M. Kettle·H. -S. Goan·Sean C. Smith·L. C. L. Hollenberg·C. J. Wellard
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Abstract

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.

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L. M. Kettle, H. -S. Goan, Sean C. Smith, L. C. L. Hollenberg, C. J. Wellard. 2004-02-06. Effects of J-gate potential and interfaces on donor exchange coupling in the Kane quantum computer architecture. https://doi.org/10.1088/0953-8984%2F16%2F7%2F001

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