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Novel Dynamical Resonances in Finite-Temperature Bose-Einstein Condensates

A. J. Geddes·S. A. Morgan·D. A. W. Hutchinson
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Abstract

We describe a variety of intriguing mode-coupling effects which can occur in a confined Bose-Einstein condensed system at finite temperature. These arise from strong interactions between a condensate fluctuation and resonances of the thermal cloud yielding strongly non-linear behaviour. We show how these processes can be affected by altering the aspect ratio of the trap, thereby changing the relevant mode-matching conditions. We illustrate how direct driving of the thermal cloud can lead to significant shifts in the excitation spectrum for a number of modes and provide further experimental scenarios in which the dramatic behaviour observed for the $m=0$ mode at JILA (Jin {\it et al.} 1997) can be repeated. Our theoretical description is based on a successful second-order finite-temperature quantum field theory which includes the full coupled dynamics of the condensate and thermal cloud and all relevant finite-size effects.

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A. J. Geddes, S. A. Morgan, D. A. W. Hutchinson. 2005-03-23. Novel Dynamical Resonances in Finite-Temperature Bose-Einstein Condensates. https://doi.org/10.1098/rspa.2005.1543

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