The Kane design of a solid state quantum-computer requires the placement of single P dopants at 20nm separation in an otherwise defect free and isotopically pure Si matrix. A formidable technological challenge indeed. A very promising approach towards such a structure is being developed by M. Simmons of the University of New South Wales (UNSW) who we are closely collaborating with. Starting with an H-terminated Si(001) surface, an STM tip is used to locally remove hydrogen and exposing a few (ideally a single) Si surface-dimers. These are reacted with PH3 gas such that only one PH3 is likely to bind. This is followed by contolled heating which incorporates P into the surface dimer. Finally, all surface H are removed and the whole structure is buried by expitaxial deposition of Si. At least thats the plan.

My job will be to provide theory support to this work. Much about the mechanistic details of how PH3 reacts and is incorporated into the surface is not at all understood.

Transparent conducting oxides (TCOs) are technologically important materials with applications in liquid-crystal- and flat-panel displays, electroactive windows, solar cells amongst others. Our research focusses on the defect chemistry of the most widely used TCO: Tin-doped indium oxide (ITO).

This work is in collaboration with Prof. L.D. Marks and his (now former) graduate student N. Erdman who have obtained partially resolved surface structures of SrTiO3 through direct methods analysis of transmission electron diffraction data. We support this work using atomistic and first-principles modeling techniques.