Sub-diffraction optical manipulation of the chargestate of nitrogen   vacancy center in diamond
  As a potential candidate for quantum computation and metrology, the nitrogen vacancy (NV)center in diamond presented both challenges and opportunities resulted from charge state conversion. By utilizing different lasers for the photon-induced charge state conversion, we achieved the sub-diffraction charge state manipulation. The charge state depletion (CSD) microscopy resolution was improved to 4.1 nm by optimizing the laser pulse sequences. Subsequently, the electron spin state dynamics of adjacent NV centers were selectively detected via the CSD. The experimental results demonstrated that the CSD can improve the spatial resolution of the measurement of NV centers for nanoscale sensing and quantum information. 
Xiangdong Chen, Changling Zou, Zhaojun Gong, Chunhua Dong, Guangcan   Guo and Fangwen Sun
quant-ph physics.optics