Quantum statistical imaging of particles without restriction of the   diffraction limit
  A practical quantum measurement method based on the quantum nature of anti-bunching photon emission has been developed to detect single particles without the restriction of the diffraction limit. By simultane- ously counting the single-photon and two-photon signals with fluorescence microscopy, the images of nearby Nitrogen-Vacancy centers in diamond at a distance of 8.5+/-2.4 nm have been successfully reconstructed. Also their axes information was optically obtained. This quantum statistical imaging technique, with a simple exper- imental setup, can also be easily generalized in the measuring and distinguishing of other physical properties with any overlapping, which shows high potential in future image and study of coupled quantum systems for quantum information techniques. 
Jin-Ming Cui, Fang-Wen Sun, Xiang-Dong Chen, Zhao-Jun Gong, and   Guang-Can Guo
quant-ph physics.optics