1. State Key Laboratory of Nuclear Physics and Technology, Institute of Heavy Ion Physics, School of Physics, Peking University, Beijing 100871, China
2. Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
3. China Nuclear Power Engineering Co., Ltd., Beijing 100840, China
4. Beijing Key Lab of Terahertz Spectroscopy and Imaging, Key Lab of Terahertz Optoelectronics, Ministry of Education, Department of Physics, Capital Normal University, Beijing 100048, China
5. Department of Materials Science and Engineering, University of Delaware, Newark, Delaware 19716, United States