arXiv:0704.1971 · Physical Review Letters
Dissipative Dynamics of Superfluid Vortices at Nonzero Temperatures
Natalia G. Berloff, Anthony J. Youd
Abstract
We consider the evolution and dissipation of vortex rings in a condensate at nonzero temperatures in the context of the classical field approximation, based on the defocusing nonlinear Schrödinger equation. The temperature in such a system is fully determined by the total number density and the number density of the condensate. The collisions with noncondensed particles reduce the radius of a vortex ring until it completely disappears. We obtain a universal decay law for a vortex line length and relate it to mutual friction coefficients in the fundamental equation of vortex motion in superfluids.