Observation of Bloch-point domain walls in cylindrical magnetic nanowires

Sandrine da Col (1) , Ségolène Jamet (1) , Nicolas Rougemaille (1) , Andrea Locatelli (2) , T.O. Mentes (2) , Benito Santos Burgos (2) , Raja Afid (1) , Michael Darques , Laurent Cagnon (1) , Jean-Christophe Toussaint (1) , Olivier Fruchart (1)

1 NEEL - MNM - Micro et NanoMagnétisme
2 ELETTRA - Elettra Light source

Topological protection is an elegant way of warranting the integrity of quantum and nanosized systems. In magnetism one example is the Bloch-point, a peculiar object implying the local vanishing of magnetization within a ferromagnet. Its existence had been postulated and described theoretically since several decades, however it has never been observed. We con rm experimentally the existence of Bloch points, imaged within domain walls in cylindrical magnetic nanowires, combining surface and transmission XMCD-PEEM magnetic microscopy. This opens the way to the experimental search for peculiar phenomena predicted during the motion of Bloch-point-based domain walls.

Domains: Materials Science [cond-mat.mtrl-sci]

Sandrine da Col, Ségolène Jamet, Nicolas Rougemaille, Andrea Locatelli, T.O. Mentes, et al.. Observation of Bloch-point domain walls in cylindrical magnetic nanowires. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2014, 89 (18), pp.180405. ⟨10.1103/PhysRevB.89.180405⟩. ⟨hal-00911025⟩