Electromagnetic Analysis and Design of Semiconductor Qubit Structures for the Realization of the Quantum Computer

Abstract

Since Kane's proposal, many researchers have been investigating the different factors that affect the performance of a quantum bit (Qubit). An important step in analyzing the Kane's system is to model the dependency of nuclear magnetic resonance (NMR) frequency on the external voltage applied via metallic gates called A-Gates. To establish this relation, we carry out a second order perturbation theory, including higher order terms up to 3d states. To design a quantum bit with an arbitrary gate structure, we use an electromagnetic simulation method to calculate the potential inside the substrate. Two new A-Gate structures are proposed and investigated rigorously by a numerical simulation method. The coplanar A-Gate structure has the advantage of easy fabrication, but it offers a relatively weak control of the NMR frequency. The split-ground A-Gate structure, on the other hand, provides a stronger voltage control over the NMR frequency of the donor atom.