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Transition from Collisionless to Hydrodynamic Behaviour in an Ultracold Atomic Gas

S. D. Gensemer·D. S. Jin
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Abstract

Relative motion in a two-component, trapped atomic gas provides a sensitive probe of interactions. By studying the lowest frequency excitations of a two spin-state gas confined in a magnetic trap, we have explored the transition from the collisionless to the hydrodynamic regime. As a function of collision rate, we observe frequency shifts as large as 6% as well as a dramatic, non-monotonic dependence of the damping rate. The measurements agree qualitatively with expectations for behavior in the collisionless and hydrodynamic limits and are quantitatively compared to a classical kinetic model.

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S. D. Gensemer, D. S. Jin. 2001-05-22. Transition from Collisionless to Hydrodynamic Behaviour in an Ultracold Atomic Gas. https://doi.org/10.1103/physrevlett.87.173201

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