[1] Fleischhauer M, Imamoglu A and Marangos J P 2005
Rev. Mod. Phys. 77 633

[2] Bergmann K, Theuer H and Shore B W 1998 Rev.
Mod. Phys. 70 1003

[3] Wu Y and Deng L 2004 Opt. Lett. 29 2064

[4] Li J H et al 2005 Chin. Phys. Lett. 22 357

[5] Li J Y et al 2005 Chin. Phys. Lett. 22 3067

[6] Fleischhauer M and Lukin M D 2000 Phys.
Rev. Lett. 84 5094

[7] Liu C et al 2001 Nature 409 490

[8] Dantan A et al 2005 Phys. Rev. Lett. 95
123002

[9] Arimondo E 1996 Progress in Optics XXXV
(Amsterdam: Elsevier)

[10] Karpati A, Kis Z and Adam P 2004 Phys. Rev. Lett.
93 193003

[11] Paspalakis E, Kylstra N J and Knight P L 2002
Phys. Rev. A 65 053808

[12] Petrosyan D and Malakyan M P 2004 Phys. Rev. A
70 023822

[13] Niu Y P, Li R X and Gong S Q 2005 Phys. Rev. A
71 043819

[14] Cohen-Tannoudji C, Dupont-Roc J and Grynberg G 1992
Atom-Photon Interactions (New York: Wiley)