Abstract
We consider the influence of a resonant control field on weak localization of light in ultracold atomic ensembles. Both steady-state and pulsed light excitation are considered. We show that the presence of a control field essentially changes the type of interference effects that occur under conditions of multiple scattering. For example, for some scattering polarization channels the presence of a control field can cause destructive interference through which the enhancement factor, normally considered to be greater than one, becomes less than one.
Acknowledgements
This work was supported by the Russian Foundation for Basic Research (Grant Nos. 08-02-91355 and 10-02-00103). M.H. acknowledges support from the National Science Foundation (NSF-PHY-0654226).