We report the observation of collective-emission-induced, velocity-dependent light forces. One-third of a falling sample containing $3\ifmmode\times\else\texttimes\fi{}{10}^{6}$ cesium atoms illuminated by a horizontal standing wave is stopped by cooperatively emitting light into a vertically oriented, confocal resonator. We observe decelerations up to $1500\text{ }\text{ }\mathrm{m}/{\mathrm{s}}^{2}$ and cooling to temperatures as low as $7\text{ }\ensuremath{\mu}\mathrm{K}$, well below the free-space Doppler limit. The measured forces substantially exceed those predicted for a single two-level atom.We report the observation of collective-emission-induced, velocity-dependent light forces. One-third of a falling sample containing $3\ifmmode\times\else\texttimes\fi{}{10}^{6}$ cesium atoms illuminated by a horizontal standing wave is stopped by cooperatively emitting light into a vertically oriented, confocal resonator. We observe decelerations up to $1500\text{ }\text{ }\mathrm{m}/{\mathrm{s}}^{2}$ and cooling to temperatures as low as $7\text{ }\ensuremath{\mu}\mathrm{K}$, well below the free-space Doppler limit. The measured forces substantially exceed those predicted for a single two-level atom.

arXiv:quant-ph/0208100Physical Review LettersFeb 14, 2003150 citations

Cooling and Cooperative Coupling of Single Atoms in an Optical Cavity

Mathematisch-naturwissenschaftlichen Fakultät I, Rheinischen Friedrich-Wilhelms-Universität Bonn

Jan 1, 20140 citations

Optomechanical Cavity Cooling of an Atomic Ensemble

Monika Schleier-Smith, Ian D. Leroux, Hao Zhang +2 more

We demonstrate cavity sideband cooling of a single collective motional mode of an atomic ensemble down to a mean phonon occupation number ⟨n⟩(min⁡)=2.0(-0.3)(+0.9). Both ⟨n⟩(min) and the observed cooling rate are in good agreement with an optomechanical model. The cooling rate constant is proportional to the total photon scattering rate by the ensemble, demonstrating the cooperative character of the light-emission-induced cooling process. We deduce fundamental limits to cavity cooling either the collective mode or, sympathetically, the single-atom degrees of freedom.We demonstrate cavity sideband cooling of a single collective motional mode of an atomic ensemble down to a mean phonon occupation number ⟨n⟩(min⁡)=2.0(-0.3)(+0.9). Both ⟨n⟩(min) and the observed cooling rate are in good agreement with an optomechanical model. The cooling rate constant is proportional to the total photon scattering rate by the ensemble, demonstrating the cooperative character of the light-emission-induced cooling process. We deduce fundamental limits to cavity cooling either the collective mode or, sympathetically, the single-atom degrees of freedom.

arXiv:1104.4623Physical Review LettersSep 28, 2011105 citations

Cavity cooling of a single atom

Peter Maunz, Thomas Puppe, I. Schuster +3 more

Abstract All conventional methods to laser-cool atoms rely on repeated cycles of optical pumping and spontaneous emission of a photon by the atom. Spontaneous emission in a random direction provides the dissipative mechanism required to remove entropy from the atom. However, alternative cooling methods have been proposed1, 2 for a single atom strongly coupled to a high-finesse cavity; the role of spontaneous emission is replaced by the escape of a photon from the cavity. Application of such cooling schemes would improve the performance of atom–cavity systems for quantum information processing3, 4. Furthermore, as cavity cooling does not rely on spontaneous emission, it can be applied to systems that cannot be laser-cooled by conventional methods; these include molecules2 (which do not have a closed transition) and collective excitations of Bose condensates5, which are destroyed by randomly directed recoil kicks. Here we demonstrate cavity cooling of single rubidium atoms stored in an intracavity dipole trap. The cooling mechanism results in extended storage times and improved localization of atoms. We estimate that the observed cooling rate is at least five times larger than that produced by free-space cooling methods, for comparable excitation of the atom.Abstract All conventional methods to laser-cool atoms rely on repeated cycles of optical pumping and spontaneous emission of a photon by the atom. Spontaneous emission in a random direction provides the dissipative mechanism required to remove entropy from the atom. However, alternative cooling methods have been proposed1, 2 for a single atom strongly coupled to a high-finesse cavity; the role of spontaneous emission is replaced by the escape of a photon from the cavity. Application of such cooling schemes would improve the performance of atom–cavity systems for quantum information processing3, 4. Furthermore, as cavity cooling does not rely on spontaneous emission, it can be applied to systems that cannot be laser-cooled by conventional methods; these include molecules2 (which do not have a closed transition) and collective excitations of Bose condensates5, which are destroyed by randomly directed recoil kicks. Here we demonstrate cavity cooling of single rubidium atoms stored in an intracavity dipole trap. The cooling mechanism results in extended storage times and improved localization of atoms. We estimate that the observed cooling rate is at least five times larger than that produced by free-space cooling methods, for comparable excitation of the atom.

Conference on Lasers and Electro-OpticsJan 1, 200425 citations

1500\text{ }\text{ }\mathrm{m}/{\mathrm{s}}^{2}

and cooling to temperatures as low as $7\text{ }\ensuremath{\mu}\mathrm{K}$, well below the free-space Doppler limit. The measured forces substantially exceed those predicted for a single two-level atom.