1. Department of Physics, Hong Kong Baptist University, Kowloon Tong, Hong Kong, China
2. State Key Laboratory of Advanced Electromagnetic Engineering and Technology, School of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
3. Potsdam Institute for Climate Impact Research, Telegraphenberg, Potsdam D-14415, Germany
4. Institute of Applied Physics of the Russian Academy of Sciences, 46 Ulyanova St., Nizhny Novgorod 603950, Russia