Revealing low-loss dielectric near-field modes of hexagonal boron nitride by photoemission electron microscopy Autor Yaolong Li, Pengzuo Jiang, Xiaying Lyu, Xiaofang Li, Huixin Qi, Jinglin Tang, Zhaohang Xue, Hong Yang, Guowei Lu, Quan Sun, Xiaoyong Hu, Yunan Gao, Qihuang Gong