M. Jona-Lasinio, K. Łakomy, L. Santos
Roton excitations constitute a key feature of dipolar gases, connecting these systems with superfluid helium. We show that the density dependence of the roton minimum results in a spatial roton confinement that is particularly relevant in pancake dipolar condensates with large aspect ratios. We demonstrate that this confinement is crucial to understand the dynamics after roton instability. We show also that arresting the instability may create a trapped roton gas revealed by confined density modulations. Roton confinement is expected to play a key role in experiments. We discuss in particular local susceptibility against density perturbations, illustrated for the case of vortices.
View original:
http://arxiv.org/abs/1301.4907
No comments:
Post a Comment