1. Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, China
2. Center for Magnetic Fusion Theory, Chinese Academy of Sciences, Hefei 230031, China
3. Advanced Energy Research Center, Shenzhen University, Shenzhen 518060, China
4. Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China