Beating Abbe diffraction limit in confocal microscopy via non-classical   photon statistics
  We experimentally demonstrate quantum enhanced resolution in confocal fluorescence microscopy exploiting the non-classical photon statistics of single nitrogen-vacancy colour centres in diamond. By developing a general model of super-resolution based on the direct sampling of the kth-order autocorrelation function of the photoluminescence signal, we show the possibility, in some cases, to resolve in principle arbitrarily close emitting centers. 
D. Gatto Monticone, K. Katamadze, P. Traina, E. Moreva, J. Forneris,   I. Ruo Berchera, P. Olivero, I. P. Degiovanni, G. Bri...
quant-ph