Strained Silicon for Quantum Computing

Strains in multivalley semiconductors can destroy the strict equivalence of the valleys that is demanded by cubic symmetry. Significant changes in the properties of a semi-conductor may result. A proposed implementation of quantum computing with donor atoms in silicon would suffer from alterations of the donor wave functions caused by strains that are produced by fabrication processes. Deliberately straining the silicon to an extent that removed all but one valley from participation in the lowest donor state would prevent further changes in the wave function by strain. The strain required can be achieved with established technology for depositing silicon on SiGe alloys.