Fig. 3: Momentum distribution of atoms and the link to localisation length.
From: Observation of two-dimensional Anderson localisation of ultracold atoms
a Numerical simulation showing the initial momentum distribution in the x and y directions, following the interaction-driven expansion after release from the harmonic trap, and prior to entering the channel (40 ms of expansion). b Distribution of initial absolute momentum value, with a mean of approximately 1.6 μm−1. The classical trapping threshold is indicated as the dashed line annotated by kth. c Theoretical localisation length as a function of ∣k∣, as calculated from Kuhn et al. for two fill-factors34. Following 250 ms of expansion in the numerical simulation, the k-distribution in the three dumbbell regions of a L = 108 μm dumbbell is plotted for three fill-factors for d the source reservoir; e the channel; and f the drain reservoir. The scale is chosen such that the integral of each distribution reflects the sum of atoms in that region of the dumbbell.
