Department of Physics, Hu'nan Normal University, Changsha 410081;
Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics,;
Department of Physics, Hu'nan Normal University, Changsha 410081;
Department of Physics, University of Waterloo, Waterloo, Ontario, N2L3G1, Canada;
Department of Physics and Atmospheric Science, Drexel University, Philadelphia, PA19104, USA;