Full configuration interaction simulations of exchange-coupled donors in silicon using multi-valley effective mass theory

Donor spin in silicon have achieved record values of coherence times and single-qubit gate fidelities. The next stage development involves demonstrating high-fidelity two-qubit logic gates, where the most natural coupling is exchange interaction. To aid efficient design scalable donor-based quantum processors, we model two-electron wave function using a full configuration interaction method within multi-valley effective mass theory. We exploit high computational efficiency our code to investigate interaction, valley population, electron densities for two phosphorus donors wide range lattice positions, orientations, as applied electric fields. outcomes are visualized with interactive images donor positions can be swept while watching orbital components evolve accordingly. Our results provide physically intuitive quantitatively accurate understanding placement tuning criteria necessary achieve gates silicon.