Proposal for electron spin relaxation measurements using double-donor excited states in Si quantum computer architectures

Abstract

The possibility of performing single-spin measurements in Si-based quantum computers using electrons bound to double donors near a barrier interface is assessed. We find that double donors in the ground state require electric fields and tunneling times too large for practical implementations, while operations with double donors in their first excited state involve smaller fields and faster tunneling times, and are therefore suitable for spin-to-charge conversion measurements. We propose a measurement scheme that would render ensemble estimates of the spin coherence at the $\mathrm{Si}∕\mathrm{Si}{\mathrm{O}}_{2}$ interface.