1998/07/30 by Maxim Olshanii, Olshanii, Maxim
Physics and Astronomy · #Atomic Physics (physics.atom-ph) #Condensed Matter (cond-mat) #FOS: Physical sciences #Fluid Dynamics (physics.flu-dyn) #Quantum Physics (quant-ph) #cond-mat #physics.atom-ph #physics.flu-dyn #quant-ph
paper · pdf · doi:10.48550/arxiv.cond-mat/9807412
4 pages, 1 figure, RevTex & PostScript
arxiv created 1998/07/31 · arxiv updated 2009/11/30
We derive a simple formula for the finite-temperature shifts of the collective excitations of a Bose-Einstein condensate. To test the validity of our treatment we apply it to explain the anomalous behavior of the ``m=2'' excitation frequency in the recent JILA experiments (D. S. Jin et al, PRL, 78 (1997) 764), where this frequency does not approach its ``noninteracting'' value at ω= 2 ωρ but, instead, decreases with temperature. It turns out that the effect is mainly governed by a resonance between the condensate excitation frequency and one of the quantum eigenfrequencies of the thermal cloud. Comparison of our predictions with the JILA experimental data shows a good agreement.