[1] CCAST (World Laboratory), P.O. Box 8730, Beijing 100080, China
[2] Physics Department 2, Fudan University, Shanghai 200433, China
[3] Joint Laboratory for Quantum Optics, Shanghai Inst. Opt. Fine Mechanics, Academy Sinica of China, Shanghai 201800, China
[4] Institute for Theoretical Physics, Justus-Liebig-University Giessen, D35392 Giessen, Germany
[5] Department of Theoretical Physics, University of New South Wales, Kensington, NSW 2033, Australia