Experimental investigation of vector static magnetic field detection using an NV center with a single first-shell 13C nuclear spin in diamond
Jiang Feng-Jian, Ye Jian-Feng, Jiao Zheng, Jiang Jun, Ma Kun, Yan Xin-Hu, Lv Hai-Jiang
       

(color online) An NV center with a nearest neighbor 13C nucleus was identified by the zero-field splitting value 126 MHz.