Roton-maxon spectrum and stability of trapped dipolar Bose-Einstein condensates.

@article{Santos2003RotonmaxonSA,
  title={Roton-maxon spectrum and stability of trapped dipolar Bose-Einstein condensates.},
  author={Luis Esteves dos Santos and Georgy V Shlyapnikov and Maciej Lewenstein},
  journal={Physical review letters},
  year={2003},
  volume={90 25 Pt 1},
  pages={250403}
}
We find that pancake dipolar condensates can exhibit a roton-maxon character of the excitation spectrum, so far observed only in superfluid helium. We also obtain a condition for the dynamical stability of these condensates. The spectrum and the border of instability are tunable by varying the particle density and/or the confining potential. This opens wide possibilities for manipulating the superfluid properties of dipolar condensates.