  The conduction band degeneracy in Si is detrimental to quantum computing
based on spin qubits, for which a nondegenerate ground orbital state is
desirable. This degeneracy is lifted at an interface with an insulator as the
spatially abrupt change in the conduction band minimum leads to intervalley
scattering. We present a theoretical study of the interface-induced valley
splitting in Si that provides simple criteria for optimal fabrication
parameters to maximize this splitting. Our work emphasizes the relevance of
different interface-related properties to the valley splitting.
