Preparation of ultracold atom clouds at the shot noise level
  We prepare number stabilized ultracold clouds through the real-time analysis of non-destructive images and the application of feedback. In our experiments, the atom number ${N\sim10^6}$ is determined by high precision Faraday imaging with uncertainty $\Delta_N$ below the shot noise level, i.e., $\Delta_N <\sqrt{N}$. Based on this measurement, feedback is applied to reduce the atom number to a user-defined target, whereupon a second imaging series probes the number stabilized cloud. By this method, we show that the atom number in ultracold clouds can be prepared below the shot noise level. 
Miroslav Gajdacz, Andrew J. Hilliard, Mick A. Kristensen, Poul L.   Pedersen, Carsten Klempt, Jan J. Arlt, Jacob F. Sherson
quant-ph physics.atom-ph