Observation of Reduced Three-Body Recombination in a Correlated 1D Degenerate Bose Gas

We investigate the correlation properties of a one-dimensional interacting Bose gas by loading a magnetically trapped Bose-Einstein condensate (BEC) into a deep two-dimensional optical lattice. We measure the three-body recombination rate for both the BEC in the magnetic trap and the BEC loaded into the optical lattice. The recombination rate coefficient is a factor of 7 smaller in the lattice, which we interpret as a reduction in the local three-body correlation function in the 1D case. This is a signature of correlation intermediate between that of the uncorrelated, phase coherent, 1D, mean-field regime and the strongly correlated Tonks-Girardeau regime.

Figure 1

Number of atoms as a function of time in the 2D lattice. The solid line is a fit to the decay as described in the text, and the dashed line is an extrapolation of the asymptotic one-body loss.

Figure 2

Number as a function of time in the tight magnetic trap (no 2D lattice). The solid line is a fit to the decay [22], and the dashed line is an extrapolation of the asymptotic one-body loss.

Figure 3

Comparison of our results with theoretical calculations of the third-order correlation function $g_3$ vs $\gamma$. The solid and short-dashed lines represent the MF and TG limits of $g_3$ from 9, and the dashed line is an estimate [28] of $g_3=(g_2{)}^3$, based on $g_2$ calculated in 12. The measured suppression factor $K_3^{\mathrm{1}\mathrm{D}}/K_3^{\mathrm{3}\mathrm{D}}$ is indicated by the box, where the height represents the measurement uncertainty and the width is the 0% to 80% range of $\gamma$ for our system.