Sub-Poissonian fluctuations in a 1D Bose gas: from the quantum quasi-condensate to the strongly interacting regime

Thibaut Jacqmin (1) , Julien Armijo (1) , Tarik Berrada (1, 2) , Karen Kheruntsyan (3) , Isabelle Bouchoule (1)

1 laboratoire Charles Fabry de l'Institut d'Optique / Optique atomique
2 Vienna Center for Quantum Science and Technology
3 ARC Centre of Excellence for Quantum-atom Optics

We report on local measurements of atom number fluctuations in slices of a single 1D Bose gas with repulsive interactions. For weakly interacting gases, the fluctuations are super-Poissonian at intermediate atomic densities and become sub-Poissonian at high densities once the gas enters into the quantum quasi-condensate regime. At stronger interactions, when approaching the fermionization regime, we no longer observe super-Poissonian statistics; the fluctuations go from Poissonian to sub-Poissonian as the density is increased, as those in a Fermi gas.

Domaines: Gaz Quantiques [cond-mat.quant-gas]; Physique Atomique [physics.atom-ph]; Optique [physics.optics]

Thibaut Jacqmin, Julien Armijo, Tarik Berrada, Karen Kheruntsyan, Isabelle Bouchoule. Sub-Poissonian fluctuations in a 1D Bose gas: from the quantum quasi-condensate to the strongly interacting regime. Physical Review Letters, 2011, 106, pp.230405. ⟨hal-00576883v4⟩