Direct numerical confirmation of pinning-induced sign change in the superconducting Hall effect in type-II superconductors

Using the time-dependent Ginzburg-Landau equation with the complex relaxation time and the Maxwell equation, we systematically examine transverse motion of vortex dynamics in the presence of pinning disorders. Consequently, in the plastic flow phase in which moving and pinned vortices coexist, we find that the Hall voltage can generally change its sign. The origin of the sign change is ascribed to the fact that moving vortices are caused to strongly drift by the circular current of pinned vortices and the enforced transverse moving direction becomes opposite to that of the transport current. This suggests that the Hall sign change is a behavior common in all disordered type-II superconductors. In this paper, we discuss conditions to observe such an intrinsic effect and explain experimental results reported in the literature on the basis of this effect.