Thermal Control of Vortex Motion in Nanoscale Superconductors

Abstract

Thermally induced motion of vortices in nanoscale superconductors (SCs) is investigated. Using numerical and analytical methods it is shown how local heating can be mapped onto an effective driving scalar potential resembling the action of a static electric field. In particular, for a local hot spot in a micron-size SC sample, a mutual attraction is found between the vortex and the hot spot that traces back to an interaction between the superconducting condensate and the superfluid velocity. It is shown that this interaction acts as an electric field resulting in a quasi Lorentz-force on the vortex. The field dependence on the material parameters of the SC as well as on pining centers is studied. It is concluded that a large magnetic penetration depth goes along with a large superfluid velocity making the vortex-hot spot attractive force stronger and leading to a mutual amplification of field and velocity. The results and analysis point to an interesting way to simulate electric field effects via local heating.