[1] Bennett C H, Brassard G and Cr\'{epeau C 1993 Phys.
Rev. Lett. 70 1895

[2] Karlsson A and Bourennane M 1999 Phys. Rev. A
58 4394

[3] Zheng S B 2006 Chin. Phys. Lett. 23 2356

[4] Zhang Y Q 2006 Chin. Phys. 15 2252

[5] Zhang Z J 2006 Phys. Lett. A 55 352

[6] Deng F G, Li C Y and Li Y S 2005 Phys. Rev. A
72 022338

[7] Dong J and Teng J F 2008 Eur. Phys. J. D 49
129

[8] Zhan X G, Li H M and Zeng H S 2006 Chin. Phys. Lett.
23 2900

[9] Li X H, Deng F G and Zhou H Y 2007 Chin. Phys. Lett.
24 1151

[10] Pati A K and Agrawal P 2004 J. Opt. B: Quantum
Semiclass. Opt. 6 S844

[11] Gordon G and Rigolin G 2006 Phys. Rev. A 73
042309

[12] Agrawal P and Pati A K 2002 Phys. Lett. A 305
12

[13] Pati A K and Agrawal P 2007 Phys. Lett. A 371
185

[14] Man Z X, Xia Y J and An N B 2007 Eur. Phys. J. D
42 333

[15] Yang C P 2004 Phys. Rev. A 70 022329

[16] Jiang W X 2007 Chin. Phys. Lett. 24 1144

[17] Li X H 2006 Phys. Rev. A 74 054302

[18] Deng F G 2006 Eur. Phys. J. D 39 459

[19] Fang J X 2003 Phys. Rev. A 67 014305