Curvature-driven ac-assisted creep dynamics of magnetic domain walls

DOMENICHINI, P.; PARIS, F.; CAPELUTO, M. G.; GRANADA, M.; GEORGE, J.-M.; PASQUINI, G.; KOLTON, A. B.

Physical Review B

American Physical Society

Año: 2021 vol. 103

2469-9950

The dynamics of micrometer-sized magnetic domains in ultrathin ferromagnetic films is so dramatically slowed down by quenched disorder that the spontaneous elastic tension collapse becomes unobservable at ambient temperature. By magneto-optical imaging we show that a weak zero-bias ac magnetic field can assist such curvature-driven collapse, making the area of a bubble to reduce at a measurable rate, in spite of the negligible effect that the same curvature has on the average creep motion driven by a comparable dc field. An analytical model explains this phenomenon quantitatively.