Dynamical Instability of a Condensate Induced by a Rotating Thermal Gas
Abstract
We study surface modes of the condensate in the presence of a rotating thermal cloud in an axisymmetric trap. By considering collisions that transfer atoms between the condensate and the noncondensate, we find that m>0 modes, which rotate in the same sense as the thermal cloud, damp less strongly than m<0 modes, where m is the polarity of the excitation. We show that above a critical angular rotation frequency, equivalent to the Landau stability criterion, m>0 modes become dynamically unstable, leading to the possibility of vortex nucleation. We also generalize our stability analysis to treat the case where the stationary state of the condensate already possesses a single vortex.
- Publication:
-
Physical Review Letters
- Pub Date:
- February 2002
- DOI:
- 10.1103/PhysRevLett.88.070401
- arXiv:
- arXiv:cond-mat/0109172
- Bibcode:
- 2002PhRvL..88g0401W
- Keywords:
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- Condensed Matter
- E-Print:
- 4 pages, no figures