Spectroscopic Evidence for an Additional Symmetry Breaking in the Nematic State of FeSe Superconductor oleh Cong Li, Xianxin Wu, Le Wang, Defa Liu, Yongqing Cai, Yang Wang, Qiang Gao, Chunyao Song, Jianwei Huang, Chenxiao Dong, Jing Liu, Ping Ai, Hailan Luo, ChaoHui Yin, Guodong Liu, Yuan Huang, Qingyan Wang, Xiaowen Jia, Fengfeng Zhang, Shenjin Zhang, Feng Yang, Zhimin Wang, Qinjun Peng, Zuyan Xu, Youguo Shi, Jiangping Hu, Tao Xiang, Lin Zhao, X. J. Zhou