Sub-Poissonian Fluctuations in a 1D Bose Gas: From the Quantum Quasicondensate to the Strongly Interacting Regime

Thibaut Jacqmin, Julien Armijo, Tarik Berrada, Karen V. Kheruntsyan, and Isabelle Bouchoule

Phys. Rev. Lett. 106, 230405 – Published 10 June 2011

Abstract

We report on local, in situ measurements of atom number fluctuations in slices of a one-dimensional Bose gas on an atom chip setup. By using current modulation techniques to prevent cloud fragmentation, we are able to probe the crossover from weak to strong interactions. For weak interactions, fluctuations go continuously from super- to sub-Poissonian as the density is increased, which is a signature of the transition between the subregimes where the two-body correlation function is dominated, respectively, by thermal and quantum contributions. At stronger interactions, the super-Poissonian region disappears, and the fluctuations go directly from Poissonian to sub-Poissonian, as expected for a “fermionized” gas.

Received 15 March 2011

DOI:https://doi.org/10.1103/PhysRevLett.106.230405

Authors & Affiliations

Thibaut Jacqmin¹, Julien Armijo¹, Tarik Berrada^1,2, Karen V. Kheruntsyan³, and Isabelle Bouchoule¹

¹Laboratoire Charles Fabry, Institut d’Optique, UMR8501 du CNRS, 91127 Palaiseau Cedex, France
²Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien, 1020 Vienna, Austria
³School of Mathematics and Physics, The University of Queensland, Brisbane, Queensland 4072, Australia