  By coating a three-dimensional topological insulator (TI) with a
ferromagnetic film supporting an in-plane magnetic vortex, one breaks the
time-reversal symmetry (TRS) without generating a mass gap. It rather yields
electronic states bound to the vortex center which have different probabilities
associated with each spin mode. In addition, its associate current (around the
vortex center) is partially polarized with an energy gap separating the most
excited bound state from the scattered ones. Charged zero-modes also appear as
fully polarized modes localized near the vortex center. From the magnetic point
of view, the observation of such a special current in a TI-magnet sandwich
comes about as an alternative technique for detecting magnetic vortices in
magnetic thin films.
