Depinning of a superfluid vortex line by Kelvin waves - art. no. 180512

We measure the interaction of a single superfluid vortex with surface irreg ularities. While vortex pinning in superconductors usually becomes weaker a t higher temperatures, we find the opposite behavior. The pinning steadily increases throughout our measurement range, from 0.15T(c) to over 0.5T(c). We also find that moving the other end of the vortex decreases the pinning, so we propose Kelvin waves along the vortex as a depinning mechanism.