Castaing's instability in a trapped ultra-cold gas
Laboratoire Kastler Brossel, Département de Physique de
l'ENS, 24 rue Lhomond, 75005 Paris, France
Published online: 15 July 2003
We consider a trapped ultra-cold gas of (non-condensed) bosons with two internal states (described by a pseudo spin) and study the stability of a longitudinal pseudo spin polarization gradient. For this purpose, we numerically solve a kinetic equation corresponding to a situation close to the experiment at JILA . It shows the presence of Castaing's instability of transverse spin polarization fluctuations at long wavelengths. This phenomenon could be used to create spontaneous transverse spin waves.
PACS: 03.75.Nt – Other Bose-Einstein condensation phenomena / 51.10.+y – Kinetic and transport theory of gases / 75.30.Ds – Spin waves
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2003