Multimode analysis of non-classical correlations in double well Bose-Einstein condensates

The observation of non-classical correlations arising in interacting two to size weakly coupled Bose-Einstein condensates was recently reported by Esteve et al. [Nature 455, 1216 (2008)]. In order to observe fluctuations below the standard quantum limit, they utilized adiabatic passage to reduce the thermal noise to below that of thermal equilibrium at the minimum realizable temperature. We present a theoretical analysis that takes into account the spatial degrees of freedom of the system, allowing us to calculate the expected correlations at finite temperature in the system, and to verify the hypothesis of adiabatic passage by comparing the dynamics to the idealized model.