Generation and detection of a sub-Poissonian atom number distribution in   a one-dimensional optical lattice
  We demonstrate preparation and detection of an atom number distribution in a one-dimensional atomic lattice with the variance $-14$ dB below the Poissonian noise level. A mesoscopic ensemble containing a few thousand atoms is trapped in the evanescent field of a nanofiber. The atom number is measured through dual-color homodyne interferometry with a pW-power shot noise limited probe. Strong coupling of the evanescent probe guided by the nanofiber allows for a real-time measurement with a precision of $\pm 8$ atoms on an ensemble of some $10^3$ atoms in a one-dimensional trap. The method is very well suited for generating collective atomic entangled or spin-squeezed states via a quantum non-demolition measurement as well as for tomography of exotic atomic states in a one-dimensional lattice. 
J.-B. B\'eguin, E. Bookjans, S. L. Christensen, H. L. S{\o}rensen, J.   H. M\"uller, J. Appel, E. S. Polzik
quant-ph physics.atom-ph