[1] Makhlin Y, Sch\"{on G and Shnirman A 2001 Rev. Mod.
Phys. 73 357

[2] Clarke J and Wilhelm F K 2008 Nature 453 1031

[3] You J Q, Tsai J S and Nori F 2002 Phys. Rev. Lett.
89 197902

[4] Lantz J, Wallquist M, Shumeiko V S and Wendin G 2004
Phys. Rev. B 70 140507(R)

[5] Wallquist M, Lantz J, Shumeiko V S and Wendin G 2005
New J. Phys. 7 178

[6] You J Q, Tsai J S and Nori F 2003 Phys. Rev. B
68 024510

[7] Plastina F and Falci G 2003 Phys. Rev. B 67
224514

[8] Zhu S L, Wang Z D and Zanardi P 2005 Phys. Rev.
Lett. 94 100502

[9] Zhu S L, Wang Z D and Yang K 2003 Phys. Rev. A
68 034303

[10] Xue Z Y and Wang Z D 2007 Phys. Rev. A 75
064303

[11] Zheng A S, Liu J B, Xiang D, Liu C L and Yuan H 2007
Chin. Phys. Lett. 24 2489

[12] Ma C, Zhang S J, He J and Ye L 2008 Chin. Phys.
Lett. 25 383

[13] Averin D V and Bruder C 2003 Phys. Rev. Lett.
91 057003

[14] Paik H et al 2005 IEEE Trans. Appl. Supercond.
15 8223

[15] Martinis J M, Nam S, Aumentado J and Lang K M 2003
Phy. Rev. B 67 094510

[16] Wen X D and YU Y 2008 Chin. Phys. Lett. 25
694

[17] Makhlin Y, Sch\"{on G and Shnirman A 1999 Nature
398 305

[18] Nakamura Y, Pashkin Y A and Tsai J S 1999 Nature
398 786

[19] Feng Z B and Zhang X D 2007 Phys. Lett. A 372
16

[20] Feng Z B and Zhang X D 2008 Physica E 40 878

[21] Xue Z Y, Wang Z D and Zhu S L 2008 Phys. Rev. A
77 024301

[22] Wu C F, Feng X L, Yi X X, Chen I M and Oh C H 2008
Phys. Rev. A 78 062321

[23] Duan L M and Guo G C 1997 Phys. Rev. Lett. 79
1953

[24] Zhu S L and Wang Z D 2003 Phys. Rev. Lett.
91 187902

[25] Lloyd S 1995 Phys. Rev. Lett. 75 346

[26] Al-Saidi W A and Stroud D 2002 Phys. Rev. B
65 224512

[27] Day P K, LeDuc H G, Mazin B, Vayonakis A and Zmuidzinas J
2003 Nature 425 817

[28] Blais A, Huang R S, Wallraff A, Girvin S M and Schoelkopf
R J 2004 Phys. Rev. A 69 062320

[29] Vion D, Aassime A, Cottet A, Joyez P, Pothier H, Urbina
C, Esteve D and Devoret M H 2002 Science 296 886