1. School of Physics, Peking University, Beijing 100871, China
2. CAS Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences (CAS), Beijing 100190, China
3. School of Physical Sciences, University of Chinese Academy of Sciences (UCAS), Beijing 100049, China
4. Asia Pacific Center for Theoretical Physics (APCTP), Pohang 37673, Republic of Korea