After a bit of reading, this is how it appears to work: For a coherent state the uncertainty relation is certainly affecting the system behaviour. In this case

After a bit of reading, this is how it appears to work: For a coherent state the uncertainty relation is certainly affecting the system behaviour. In this case, the standard deviation of the position times the devotion in speed/moment is h-bar/2 However, the effect in this case is evident in a Heisenberg limited momentum, as the spatial dimension/position of the condensate becomes well defined by the physical dimensions of the trap. Sources: * Wikipedia on Heisenberg uncertainty for Coherent states ( BECs exhibit a close to ideal coherent state ) * Observing Properties of an Interacting Homogeneous Bose--Einstein Condensate: Heisenberg-Limited Momentum Spread, Interaction Energy and Free-Expansion Dynamics https://arxiv.org/abs/1403.7081 https://arxiv.org/abs/1403.7081 * Guesstimations and extrapolations.