1School of Optoelectronic Engineering, Xidian University, Xi’an 710071, China
2School of Physics, Xidian University, Xi’an 710071, China
3Laboratoire Kastler Brossel, ENS–Université PSL, CNRS, Sorbonne Université, College de France, F-75005 Paris, France
4Hefei National Laboratory for Physical Sciences at Microscale and School of Physical Science, University of Science and Technology of China, Hefei 230026, China