Deterministic atom placement by ion implantation: Few and single atom devices for quantum computer technology

Abstract

We describe an approach to quantum computer technology based on engineered single donor atoms implanted into silicon. We exploit quantum superposition and entanglement in potentially scalable nanoscale quantum devices engineered with just a single phosphorus donor atom in a silicon nano-scale complementary metal-oxide-semiconductor device. The devices are sensitive to the variation in the position of the donor atoms and also, when cooled to 100 mK, to the quantum state of single donors. Over the past two years we have fabricated devices incorporating 31P donor atoms implanted 20 nm deep into isotopically enriched 28Si followed by rapid thermal annealing at 1000oC for 5 s to activate the dono..