Single particle microscopy with nanometer resolution
  We experimentally demonstrate nanoscopic transmission microscopy relying on a deterministic single particle source. This increases the signal-to-noise ratio with respect to conventional microscopy methods, which employ Poissonian particle sources. We use laser-cooled ions extracted from a Paul trap, and demonstrate remote imaging of transmissive objects with a resolution of 8.6 $\pm$ 2.0nm and a minimum two-sample deviation of the beam position of 1.5nm. Detector dark counts can be suppressed by 6 orders of magnitudes through gating by the extraction event. The deterministic nature of our source enables an information-gain driven approach to imaging. We demonstrate this by performing efficient beam characterization based on a Bayes experiment design method. 
Georg Jacob, Karin Groot-Berning, Sebastian Wolf, Stefan Ulm, Luc   Couturier, Ulrich G. Poschinger, Ferdinand Schmidt-Kaler...
physics.atom-ph quant-ph