[1] Hunan Inst Technol, Dept Math & Phys, Hengyang 421002, Peoples R China
[2] Hunan Normal Univ, Key Lab Low Dimens Quantum Struct & Quantum Contr, Synerget Innovat Ctr Quantum Effects & Applicat, Minist Educ,Sch Phys & Elect, Changsha 410081, Peoples R China
[3] Xiangtan Univ, Sch Phys & Optoelect Engn, Xiangtan 411105, Peoples R China