arXiv:cond-mat/0211396 · Physical Review Letters
Beliaev Damping and Kelvin Mode Spectroscopy of a Bose-Einstein Condensate in the Presence of a Vortex Line
Takeshi Mizushima, Masanori Ichioka, K. Machida
Abstract
It is demonstrated theoretically that the counter-rotating quadrupole mode in a vortex of Bose-Einstein condensates can decay into a pair of Kelvin modes via the Beliaev process. We calculate the spectral weight of a density-response function within the Bogoliubov framework, taking account of both Beliaev and Landau processes. Good agreement with experiment on 87 Rb by Bretin et al. [Phys. Rev. Lett., 100403 (2003)]] allows us to unambiguously identify the decayed mode as the Kelvin wave propagating along a vortex line.