On the dynamics of a quantum-statistical condensate

Pavlo Shygorin, Svidzynskyi, Anatolii V., Свідзинський, Анатолій Вадимович +1 more

Starting from first principles of the statistical mechanics we construct\na dynamics of the condensed Bose gas at the nonzero\ntemperatures. In particular, we derive an equation of motion for\nthe condensate wavefunction and a quantum kinetic equation for\nthe distribution function for the excited atoms. Obtained generalized\nGross-Pitaevskii equation for condensate include effect of\ncollisions with thermal cloud atoms (non-condensate). The Boltzmann\nquantum kinetic equation for non-condensate was obtained\nusing Zubarev’s method of nonequilibrium statistical operator.\nTherefore was obtained a complete dynamics of the condensed\nBose gas at the nonzero temperatures.

Derek W. Robinson

Vito Barbarani

Guangri Jin, Chul Koo Kim, Kyun Nahm

Based on a two-mode boson model, we study nonclassical properties of the atom-molecule Bose-Einstein condensate. The effects of nonlinear collisions on the dynamics of the molecular formation is studied both in classical and quantum treatments. We find that the conversion from atoms to molecules can be suppressed strongly due to nonlinearity induced localization of the atomic population. In addition, we study statistical properties of the atom-molecule condensed system by calculating the intensity correlation functions numerically. We find that the effect of nonlinearity leads to the appearance of superchaotic molecular pulses, while maintaining the atomic field sub-Poissonian. The joint quantum statistical properties of the atoms and the molecules always show antibunching.

Su Yi, Özgür Esat Müstecaplıoğlu, Li You

M. K. Olsen, Lev I. Plimak

We show that the photoassociation of an atomic Bose-Einstein condensate to form condensed molecules is a chemical process which not only does not obey the Arrhenius rules for chemical reactions, but that it can also depend on the quantum statistics of the reactants. Comparing the predictions of a truncated Wigner representation for different initial quantum states, we find that, even when the quantum prediction for an initial coherent state is close to the Gross-Pitaevskii prediction, other quantum states may result in very different dynamics.