arXiv:1006.4315 · Physical Review B
Anomalous vortex-ring velocities induced by thermally excited Kelvin waves and counterflow effects in superfluids
Giorgio Krstulovic, Marc Brächet
Abstract
Dynamical counterflow effects on vortex evolution under the truncated Gross-Pitaevskii equation are investigated. Standard longitudinal mutual-friction effects are produced and a dilatation of vortex rings is obtained at large counterflows. A strong temperature-dependent anomalous slowdown of vortex rings is observed and attributed to the presence of thermally excited Kelvin waves. This generic effect of finite-temperature superfluids is estimated using energy equipartition and orders of magnitude are given for weakly interacting Bose-Einstein condensates and superfluid $^{4}\mathrm{He}$. The relevance of thermally excited Kelvin waves is discussed in the context of quantum turbulence.