Send to

Choose Destination
Nat Commun. 2016 Mar 17;7:11039. doi: 10.1038/ncomms11039.

Collective atomic scattering and motional effects in a dense coherent medium.

Author information

JILA, NIST and Department of Physics, University of Colorado, 440 UCB, Boulder, Colorado 80309, USA.
Université de Nice Sophia Antipolis, CNRS, Institut Non-Linéaire de Nice, UMR 7335, F-06560 Valbonne, France.
Department of Physics, University of Connecticut, Storrs, Connecticut 06269, USA.
Department of Physics, Harvard University, Cambridge, Massachussetts 02138, USA.


We investigate collective emission from coherently driven ultracold (88)Sr atoms. We perform two sets of experiments using a strong and weak transition that are insensitive and sensitive, respectively, to atomic motion at 1 μK. We observe highly directional forward emission with a peak intensity that is enhanced, for the strong transition, by >10(3) compared with that in the transverse direction. This is accompanied by substantial broadening of spectral lines. For the weak transition, the forward enhancement is substantially reduced due to motion. Meanwhile, a density-dependent frequency shift of the weak transition (∼10% of the natural linewidth) is observed. In contrast, this shift is suppressed to <1% of the natural linewidth for the strong transition. Along the transverse direction, we observe strong polarization dependences of the fluorescence intensity and line broadening for both transitions. The measurements are reproduced with a theoretical model treating the atoms as coherent, interacting radiating dipoles.

Supplemental Content

Full text links

Icon for Nature Publishing Group Icon for PubMed Central
Loading ...
Support Center