12 N$_{lm}$ ( r ) = − ( − i ) l $^{+1}$e ikr k √ l ( l + 1)$^{∇}$ Y$_{lm}$ (ˆ r ) , (66) G s $_{µν}$( r , r $^{′}$) = 1 k 2 ∑ lm ¯ α$_{l}$ (2 l + 1) ψ µ $_{lm}$( r ) ψ ν ∗ $_{lm}$( r $^{′}$) − i ks$_{1}$ 3 1 ∑ m = − 1 [ ˜ α$_{1}$ [ ψ µ 1 $_{m}$( r ) χ ν ∗ 1 $_{m}$( r $^{′}$) + χ µ 1 $_{m}$( r ) ψ ν ∗ 1 $_{m}$( r $^{′}$) ] −| ˜ α$_{1}$ | $^{2}$ψ µ 1 $_{m}$( r ) ψ ν ∗ 1 $_{m}$( r $^{′}$) ] , (65) G s $_{µν}$( r , r $^{′}$) = − ˜ α$_{1}$ 3 1 ∑ m = − 1 e $^{ikr}$[ ∇ $_{µ}$Y$_{1}$$_{m}$ (ˆ r ) ] ψ ν ∗ 1 $_{m}$( r $^{′}$) , (67) For kr ≫ 1, with help of Eqs. (51), (59), and (60), we easily obtain This expression can be further simplified by substituting ˜ α$_{l}$ = ¯ α$_{l}$ + is$_{l}$k 2 l $^{+1}$| ˜ α$_{l}$ | $^{2}$, where ¯ α$_{l}$ = α$_{l}$ | 1 − is$_{l}$k 2 l $^{+1}$α$_{l}$ | − $^{2}$, and keeping the first two powers of k and combining this expression with Eq. (62), we obtain the far field Green dyadic (i.e., kr ≫ 1 and kr ′ ≪ 1) where we set l = 1. which, after adding the free-space part of the Green dyadic and neglecting plasmon radiative decay, leads to Eq. (12). Reinhoudt, M. Moller, and D. I. Gittins, Phys. Rev. Lett. 89 , 203002 (2002). 1 R. H. Dicke, Phys. Rev. 93 , 99 (1954). 2 M. Gross and S. Haroche, Phys. Rep. 93 , 301 (1982). 3 A. V. Andreev, V. I. Emel’yanov, and Yu. A. Il’inskii, Co- operative Effects in Optics (IOP Publishing, 1993). 4 T. Brandes, Phys. Rep. 408 , 315 (2005). 16 E. Dulkeith, M. Ringler, T. A. Klar, J. Feldmann, A. M. Javier, and W. J. Parak, Nano Lett. 5 , 585 (2005). 17 P. Anger, P. Bharadwaj, and L. Novotny, Phys. Rev. Lett. 96 , 113002 (2006). 18 S. K¨ uhn, U. Hakanson, L. Rogobete, and V. Sandoghdar, Phys. Rev. Lett. 97 , 017402 (2006). 19 F. Tam, G. P. Goodrich, B. R. Johnson, and N. J. Halas, Nano Lett. 7 , 496 (2007). 5 R.G. DeVoe and R.G. Brewer, Phys. Rev. Lett. 76 , 2049 (1996). 6 M. Scheibner, T. Schmidt, L. Worschech, A. Forchel, G. Bacher, T. Passow, and D. Hommel, Nature Phys. 3 , 106 (2007). 20 J. Gersten and A. Nitzan, J. Chem. Phys. 75 , 1139 (1981). 21 R. Ruppin, J. Chem. Phys. 76 , 1681 (1982). 22 A. Pineda and D. J. Ronis, J. Chem. Phys. 83 , 5330 (1985) 23 H. Chew, J. Chem. Phys. 87 , 1355 (1987). 24 F. C. Spano and S. Mukamel, J. Chem. Phys. 91 , 683 (1989) 7 T.V. Shahbazyan, M.E. Raikh, Phys. Rev. B 49, 17123 (1994). 8 T. V. Shahbazyan and S. E. Ulloa, Phys. Rev. B 57 , 6642 (1998). 9 T. Brandes and B. Kramer, Phys. Rev. Lett. 83 , 3021 (1999). 25 T. V. Shahbazyan, M. E. Raikh, and Z. V. Vardeny, Phys. Rev. B 61 , 13266 (2000). 10 V. N. Pustovit and T. V. Shahbazyan, Phys. Rev. Lett. 102 , 077401 (2009). 11 R. R. Chance, A. Prock, and R. Silbey, Adv. Chem. Phys. 37 , 1 (1978). 26 M. I. Stockman, Phys. Rev. Lett. 79 , 4562 (1997). 27 J. Seelig, K. Leslie, A. Renn, S. K1uhn, V. Jacobsen, M. van de Corput, C. Wyman, and V. Sandoghdar, Nano Lett. 7 , 685 (2007). 28 M. Durach, A. Rusina, V. I. Klimov, and M. I. Stockman, New J. Phys. 10 , 105011 (2008). 12 B. N. J. Persson and N. D. Lang, Phys. Rev. B 26 , 5409 (1982). 13 I. A. Larkin, M. I. Stockman, M. Achermann, and V. I. Klimov, Phys. Rev. B 69 , 121403(R) (2004). 14 M. Moskovits, Rev. Mod. Phys. 57 , 783 (1985). 15 E. Dulkeith, A. C. Morteani, T. Niedereichholz, T. A. Klar, J. Feldmann, S. A. Levi, F. C. J. M.. van Veggel, D. N. 29 L. Novotny, Principles of Nano-Optics , (Cambridge Uni- versity Press, 2006).