Evidence for domain wall tunnelling in a quasi-one dimensional ferromagnet

We have studied the motion of magnetic domain walls in very small diameter ferromagnetic wires. Our results suggest that walls do not move smoothly along the wire, but can be trapped at pinning sites. It appears that they escape from these sites by thermal activation at high temperatures, and quantum tunnelling at low temperatures. Tunnelling dominates below similar to 5 K, which is about an order of magnitude higher than predicted by the current theory.