Evidence of a two-dimensional nitrogen crystalline structure on silver surfaces

X Xuegao Hu (Institute of Physics, Chinese Academy of Sciences) H Haijun Cao Z Zhicheng Gao (Institute of Physics) H Hui Zhou (Department of Chemistry and Materials) D Daiyu Geng D Dong Li J Jisong Gao (Institute of Physics, Chinese Academy of Sciences) Q Qiaoxiao Zhao (Institute of Physics) Z Zhihao Cai P Peng Cheng (College of Chemistry, Frontiers Science Center for New Organic Matter) L Lan Chen S Sheng Meng (Institute of Physics) K Kehui Wu (Tsientang Institute for Advanced Study) B Baojie Feng (Institute of Physics, Chinese Academy of Sciences)