[1] Hong Kong Baptist Univ, Dept Phys, Hong Kong, Hong Kong, Peoples R China
[2] Univ Sci & Technol China, Key Lab Quantum Commun & Quantum Computat, Hefei 230026, Peoples R China
[3] Natl Univ Def Technol, Dept Phys, Changsha 410073, Peoples R China
[4] Chinese Univ Hong Kong, Inst Theoret Phys, Hong Kong, Hong Kong, Peoples R China