1. Department of Physics, The City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong SAR 999077, China
2. City University of Hong Kong Shenzhen Research Institute, 8 Yuexing First Road, Gaoxin District, Shenzhen 518057, China
3. School of Physics and Technology, Wuhan University, Wuhan 430072, China