Abstract for the talk on 28.11.2017 (17:00 h)Colloquium of the Faculty of Physics and Geosciences
Ferdinand Schmidt-Kaler (Johannes Gutenberg Universität Mainz)
Single ion microscopy and single ion implantation for novel quantum technologies
Quantum technologies allow for fully novel schemes of computing, simulation and sensing. For quantum computing, we employ trapped ions in modern segmented ion traps as scalable and freely reconfigurable qubit register . I will give an overview of the recent progress, where gate fidelities of 99.995% (single bit) and 99.6% (two bit) are reached. Alternative platforms for quantum computers in solid state technology would largely benefit from determinsitic schemes to fabricate qubit registers with nm-accuray. I describe our deterministic ion source, which allows for delivering Ca+ ions on demand and focus it into a spot of a few nm . The source can be operated with any other doping ion, which is co-trapped and sympathetically cooled together with a single Ca+ ion, eventually extracted and implanted. We have started structuring solid state samples such as diamond with N2+ molecular ions to generate NV centers, rate-earth Presodym or Cer ions  in YAG samples and will start implanting P+ ions into ultrapure Silicium , with the vision to fabricate
devices for quantum information processing.
 Kaufmann er al, Phys. Rev. Lett. 119, 150503 (2017)
 Jacob et al, Phys. Rev. Lett. 117, 043001 (2016)
 Kornher et al, Appl. Phys. Lett. 108, 053108 (2016),
 van Donkelaar et al, J. Phys.: Condens. Matter 27, 154204 (2015),
Implantation pattern of Pr+ with distance 2µm and spot size of about 30nm.
The confocal optical microscope has a 200nm resolution. Background
spots are from imurity ions which have been before in the host crystal.