S. Ghosh, U. Roy, C. Genes and D. Vitali, Phys. Rev. A [**79**]{}, 052104 (2009).

F. Toscano, D. A. R. Dalvit, L. Davidovich and W. H. Zurek, Phys. Rev. A [**73**]{}, 023803 (2006).

D. A. R. Dalvit, R. L. de M. Filho and F. Toscano, New Journal of Physics [**8**]{}, 276 (2006).

L. Praxmeyer, P. Wasylczyk, C. Radzewicz and K. Wódkiewicz, Phys. Rev. Lett. [**98**]{}, 063901 (2007).

S. Ghosh, A. Chiruvelli, J. Banerji and P. K. Panigrahi, Phys. Rev. A [**73**]{}, 013411 (2006).

J. R. Bhatt, P. K. Panigrahi and M. Vyas, Phys. Rev. A [**78**]{}, 034101 (2008).

M. Stobinska, G. J. Milburn and K. Wódkiewicz, Phys. Rev. A [**78**]{}, 013810 (2008).

J. Banerji, Contemporary Physics [**48**]{}, 157 (2007).

A. J. Scott and S. M. Caves, Annals of Physics [**323**]{}, 2685 (2008).

B. Y. Tong, Solid State Commun. [**104**]{}, 679 (1997).

B. Y. Tong and N. Kiriushcheva, Phys. Lett. A [**229**]{}, 49 (1997).

J. Radovanovic, V. Milanavic, Z. Ikonic and D. Indjin, Phys. Lett. A [**269**]{}, 179 (2008).

H. Yildirim and M. Tomak, Phys. Rev. B, [**72**]{}, 115340 (2005).

H. Yildirim and M. Tomak, J. App. Phys. [**99**]{}, 093103 (2006).

I. Sh Averbukh and N. F. Perelman, Phys. Lett. A 