Weak localisation of light by atoms with quantum internal structure

Abstract

The interference contrast observed in coherent backscattering by cold atoms is drastically reduced with respect to classical disordered media. We study the impact of the degeneracy of the resonant atomic dipole transition on multiple scattering of polarised photons. An analytical treatment allows to derive the diffusion coefficient and depolarisation times for the average light intensity, and dephasing times for the weak localisation corrections. The calculated CBS signals reproduce the experimental results.

14 pages, to appear in "Wave Scattering in Complex Media: From Theory to Applications" ed. by B.A. van Tiggelen and S.E. Skipetrov