Collisional Narrowing and Dynamical Decoupling in a Dense Ensemble of Cold Atoms

Yoav Sagi, Ido Almog, Nir Davidson

Ludwig Mathey, Eite Tiesinga, Paul S. Julienne +1 more

Yoav Sagi

Yoav Sagi, Ido Almog, Nir Davidson

We study the spectral narrowing induced by collisions in a dense cold atomic ensemble. We report on experiments showing a prolongation of the coherence time of optically trapped 87Rb atoms as the density increases, a phenomenon we call collisional narrowing in analogy to the motional narrowing effect in NMR. We derive an expression for the new dephasing time scale in terms of the collision rate and the inhomogeneous decay time. Remarkably, this time scale universally depends only on the atomic phase space density.

Alexandra Bakman, Shmuel Fishman

Yoav Sagi, Ido Almog, Nir Davidson

We employ dynamical decoupling techniques to suppress the decoherence induced by elastic collisions in optically trapped 87Rb atoms. Coherence times exceeding 3 sec in a dense ensemble are demonstrated for an arbitrary initial state.