Hall voltage sign reversal in thin superconducting films

Abstract

A novel approach to the superconducting Hall effect is developed, based on the opposing drift of the thermally excited quasiparticles. These collide quasielastically with the hydrodynamic superfluid velocity field circulating far outside the core of a vortex, thereby transferring momentum to the latter. The predicted Hall angle, by BCS theory, is of the order of ${\mathit{k}}_{\mathit{B}}$ ${\mathit{T}}_{\mathit{c}}$ divided by the Fermi energy, has sign opposite to that in the normal state, because of the backflow, and disappears at low temperature.