External field control of donor electron exchange at the Si/SiO2 interface

Abstract

We analyze several important issues for the single- and two-qubit operations in Si quantum computer architectures involving P donors close to a SiO2 interface. For a single donor, we investigate the donor-bound electron manipulation (i.e. 1-qubit operation) between the donor and the interface by electric and magnetic fields. We establish conditions to keep a donor-bound state at the interface in the absence of local surface gates, and estimate the maximum planar density of donors allowed to avoid the formation of a 2-dimensional electron gas at the interface. We also calculate the times involved in single electron shuttling between the donor and the interface. For a donor pair, we find that under certain conditions the exchange coupling (i.e. 2-qubit operation) between the respective electron pair at the interface may be of the same order of magnitude as the coupling in GaAs-based two-electron double quantum dots where coherent spin manipulation and control has been recently demonstrated (for example for donors ~10 nm below the interface and \~40 nm apart, J~10^{-4} meV), opening the perspective for similar experiments to be performed in Si.

11 pages, 15 figures. Changes in Eq. 24 plus minor typos

References in corpus (5)

• Driven coherent oscillations of a single electron spin in a quantum dot
• Electrical detection of 31P spin quantum states
• Electron spin phase relaxation of phosphorus donors in nuclear spin enriched silicon
• Quantum control of donor electrons at the Si-SiO2 interface
• Electrical readout of a spin qubit without double occupancy

Cited by in corpus (4)

• Quantum control and manipulation of donor electrons in Si-based quantum computing
• Reliability of the Heitler-London approach for the exchange coupling between electrons in semiconductor nanostructures
• Valley interference effects on a donor electron close to a Si/SiO2 interface
• Single electron spin and its coherence in Si quantum computer architecture