D ec 2 02 0 Observation of quantum spin Hall states in Ta 2 Pd

Xuguang Wang, 4, 7 Daiyu Geng, 4, 7 Dayu Yan, 4, 7 Wenqi Hu, 4, 7 Hexu Zhang, 4 Shaosheng Yue, 4 Zhenyu Sun, 4 Shiv Kumar, Kenya Shimada, Peng Cheng, 4 Lan Chen, 4, 6 Simin Nie, Zhijun Wang, 4 Youguo Shi, 4, 5, 6, ∗ Yi-Qi Zhang, 4 Kehui Wu, 4, 6, † and Baojie Feng 4, ‡ Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China Hiroshima Synchrotron Radiation Center, Hiroshima University, 2-313 Kagamiyama, Higashi-Hiroshima 739-0046, Japan Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, USA School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China These authors contributed equally to this work. (Dated: December 15, 2020)