3D Magnetic Möbius Band

Three-dimensional (3D) nanomagnetic structures provide fertile ground for stabilizing complex spin configurations, as their local curvature intricately modifies the energy landscape [1, 2]. To gain a comprehensive understanding, it is essential to explore how curvature influences magnetic characteristics such as topology and chirality, which ultimately govern the overall magnetic configuration. To examine this, we fabricated 3D Möbius bands using two-photon polymerization nanolithography, followed by magnetron sputtering to deposit a Fe (40 nm)/Ta (2 nm) thin film which formed a magnetic replica of the Möbius band. Magnetometry and first-order reversal curve (FORC) exhibited a striking difference in the magnetization reversal mechanism between in-plane and out-of-plane fields, with step-like switching occurring in the latter. Micromagnetic simulations revealed that the curvature of the band lead to preferential domain wall formation and propagation. Additionally, X-ray Magnetic Circular Dichroism (XMCD) imaging was used to visualize magnetic domains. These comprehensive studies provide valuable insights into the fundamental relationships between spin texture and the geometry of 3D nanomagnetic structures.

[1] Fischer et. al., APL Materials 8 (1), 010701 (2020).

[2] Pylypovskyi et. al., Phys. Rev. Lett. 114, 197204 (2015).