Crossed ratchet effects for magnetic domain wall motion

We study both experimentally and theoretically the driven motion of domain walls in extended amorphous magnetic films patterned with a periodic array of asymmetric holes. We find two crossed ratchet effects of opposite sign that change the preferred sense for domain wall propagation, depending on whether a flat or a kinked wall is moving. By solving numerically a simple $\phi^4$-model we show that the essential physical ingredients for this effect are quite generic and could be realized in other experimental systems involving elastic interfaces moving in multidimensional ratchet potentials.