Implantation of countable single nitrogen ions and the nitrogen vacancy (NV) center creation efficiency
Jan Meijer (Universität Leipzig)

The key technology to fabricate quantum devices, i.e. devices that employ single atoms or defects as functional unit is the addressing of single atoms in a solid with high lateral resolu-tion. Whereas the manipulation of single atoms at the surface has been possible since several years, the three dimensional addressing in the bulk requires more effort. The combination of surface manipulation and overgrowth is one possibility but technologically very challenging. Ion beam implantation allows addressing single countable atoms inside a given solid with nanometer precision. To meet this goal we firstly need to focus or collimate the ion beam and to count the ions delivered to the sample. Our approach is to detect a single ion during fly-by using image charge detection and to deliver the ion with nanometer precision employ-ing a modified commercial FIB system.
However, to create a deterministic quantum register based on NV centers a third requirement has to be considered: The implanted nitrogen atom has to be converted into an NV center with nearly 100% efficiency. Unfortunately, the creation of vacancies by ion impact is a statistical process and therefore not predictable. Additionally, the charge state of the NV center has to be converted into the negative state to make it functional.
The talk will discuss the state of the art of single ion nano-implantation methods as well as new developments in material science to overcome the limitations encountered in the crea-tion of NV centers so far.