We present highly efficient emission of twin-atom beams into a single
transversal mode of a waveguide potential. The source is a one-dimensional
degenerate Bose gas in the first radially excited state. We directly measure a
suppression of fluctuations in the atom number difference between the beams to
0.37(3) with respect to the classical expectation, equivalent to 0.11(2) after
correcting for detection noise. Our results underline the high potential of
ultracold atomic gases as sources for quantum matter wave optics and will
enable the implementation of schemes previously unattainable with massive
particlesComment: 7 pages (including supplementary material), 5 figure
We measure the two-point density correlation function of freely expanding quasicondensates in the weakly interacting quasi-one-dimensional (1D) regime. While initially suppressed in the trap, density fluctuations emerge gradually during expansion as a result of initial phase fluctuations present in the trapped quasicondensate. Asymptotically, they are governed by the thermal coherence length of the system. Our measurements take place in an intermediate regime where density correlations are related to near-field diffraction effects and anomalous correlations play an important role. Comparison with a recent theoretical approach described by Imambekov et al. yields good agreement with our experimental results and shows that density correlations can be used for thermometry of quasicondensates.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.