Grant: Research Tools and Instruments - Category 1 (<$150,000)

Silicon is by far the most important semiconductor in the electronics, information and communications sectors, and the understanding of the physics of impurities and defects in Si is highly advanced, as is Si materials and device technology. As with almost all semiconductors, Si has more than one stable isotope, and all existing Si devices are based on natural Si, which is a mixture of these three stable isotopes. We have recently discovered that the linewidths of many of the well-studied impurity and defect transitions in highly isotopically enriched 28Si are much narrower than previously observed in the purest and most perfect natural Si. The greatly improved spectral resolution obtainable in 28Si has enabled us to make a number of exciting and unexpected discoveries, some of which may lead to applications in quantum computing and quantum information systems. In particular, we have shown that it is possible in 28Si to measure the tiny nuclear spins of defects such as 31P and 77Se, and possibly also to control these nuclear spins through optical means. The requested high homogeneity magnet system will allow us to investigate these effects as a function of magnetic field, to look for new physics and the possibility of new applications.