Sub-Poissonian atom number fluctuations using light-assisted collisions

Abstract

We investigate experimentally the number statistics of a mesoscopic ensemble of cold atoms in a microscopic dipole trap loaded from a magneto-optical trap, and find that the atom number fluctuations are reduced with respect to a Poisson distribution due to light-assisted two-body collisions. For numbers of atoms N>2, we measure a reduction factor (Fano factor) of 0.72+/-0.07, which differs from 1 by more than 4 standard deviations. We analyze this fact by a general stochastic model describing the competition between the loading of the trap from a reservoir of cold atoms and multi-atom losses, which leads to a master equation. Applied to our experimental regime, this model indicates an asymptotic value of 3/4 for the Fano factor at large N and in steady state. We thus show that we have reached the ultimate level of reduction in number fluctuations in our system.

4 pages, 3 figures

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Cited by in corpus (12)

• Coherent scattering of near-resonant light by a Dense Microscopic Cold Atomic cloud
• Generation and detection of a sub-Poissonian atom number distribution in a one-dimensional optical lattice
• Study of light-assisted collisions between a few cold atoms in a microscopic dipole trap
• Propagation of light through small clouds of cold interacting atoms
• Entanglement-enhanced phase estimation without prior phase information
• Integrated Optical Dipole Trap for Cold Neutral Atoms with an Optical Waveguide Coupler
• Entanglement of Two Atoms using Rydberg Blockade
• Optical Tweezer Arrays of Erbium Atoms
• In-trap fluorescence detection of atoms in a microscopic dipole trap
• Controllable atomic collision in a tight optical dipole trap
• Quantifying Light-assisted Collisions in Optical Tweezers Across the Hyperfine Spectrum
• Sub-Poissonian atom-number distributions by means of Rydberg dressing and electromagnetically induced transparency