Theoretical Calculation of the Magnetic Resonance Frequency of the Electron Spin Embedded Inside a Silicon Host for Solid-State Quantum Computing

The electron-spin magnetic resonance frequency of an electron-spin qubit structure that is proposed for the realization of a quantum computer is rigorously determined by a numerical method. The potential distribution inside the silicon qubit structure is accurately calculated by an electromagnetic simulation method, and the perturbation theory to the second order is formulated to obtain the magnetic resonance frequency of a phosphorus donor electron spin. Our results showed that, for the same qubit structure (Si:P), as originally proposed by Kane for a nuclear-spin qubit quantum computer, a smaller static magnetic field B is in favor of producing a wider tunable bandwidth for the magnetic resonance frequency of the electron spin. Our results also reveal that the use of SiGe as an alternative insulation material to the A-gate structure can improve the control efficiency of the A-gate voltage.