Homogenization of an ensemble of interacting resonant scatterers
| Autor: | Schilder, N. J., Sauvan, C., Sortais, Y. R. P., Browaeys, A., Greffet, J. -J. |
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| Rok vydání: | 2017 |
| Předmět: | |
| Zdroj: | Phys. Rev. A 96, 013825 (2017) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevA.96.013825 |
| Popis: | We study theoretically the concept of homogenization in optics using an ensemble of randomly distributed resonant stationary atoms with density $\rho$. The ensemble is dense enough for the usual condition for homogenization, viz. $\rho\lambda^3 \gg 1$, to be reached. Introducing the coherent and incoherent scattered powers, we define two criteria to define the homogenization regime. We find that when the excitation field is tuned in a broad frequency range around the resonance, none of the criteria for homogenization is fulfilled, meaning that the condition $\rho\lambda^3\gg 1$ is not sufficient to characterize the homogenized regime around the atomic resonance. We interpret these results as a consequence of the light-induced dipole-dipole interactions between the atoms, which implies a description of scattering in terms of collective modes rather than as a sequence of individual scattering events. Finally, we show that, although homogenization can never be reached for a dense ensemble of randomly positioned laser-cooled atoms around resonance, it becomes possible if one introduces spatial correlations in the positions of the atoms or non-radiative losses, such as would be the case for organic molecules or quantum dots coupled to a phonon bath. Comment: 9 pages, 5 figures. Corrected mistakes in references |
| Databáze: | arXiv |
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