Critical Superfluid Velocity in a Trapped Dipolar Gas
- JILA and Department of Physics, University of Colorado, Boulder, Colorado 80309-0440 (United States)
We investigate the superfluid properties of a dipolar Bose-Einstein condensate (BEC) in a fully three-dimensional trap. Specifically, we estimate a superfluid critical velocity for this system by applying the Landau criterion to its discrete quasiparticle spectrum. We test this critical velocity by direct numerical simulation of condensate depletion as a blue-detuned laser moves through the condensate. In both cases, the presence of the roton in the spectrum serves to lower the critical velocity beyond a critical particle number. Since the shape of the dispersion, and hence the roton minimum, is tunable as a function of particle number, we thereby propose an experiment that can simultaneously measure the Landau critical velocity of a dipolar BEC and demonstrate the presence of the roton in this system.
- OSTI ID:
- 21386830
- Journal Information:
- Physical Review Letters, Vol. 104, Issue 9; Other Information: DOI: 10.1103/PhysRevLett.104.094501; (c) 2010 The American Physical Society; ISSN 0031-9007
- Country of Publication:
- United States
- Language:
- English
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