1. Institute of Large-Scale Scientific Facility and Centre for Zero Magnetic Field Science, Beihang University, Beijing, China
2. School of Automation Science and Electrical Engineering, Beihang University, Beijing, China
3. School of Physics and the School of Instrumentation and Optoelectronic Engineering, Beihang University, Beijing, China
4. School of Instrumentation and Optoelectronic Engineering, Beihang University, Beijing, China