Thickness-driven transitions between magnetic states in ferromagnetic films

Magnetic materials hosting stable topological spin textures have demonstrated energy efficiency and potential as information carriers in logic and memory devices, offering an alternative to magnetic tunnel junction technology. While these structures are well understood in two dimensions (2D), in 3D their stability, interactions, and topological transitions require further exploration. Here we present two thermodynamically stable topological states, termed the ``hourglass'' and ``dome,'' in centrosymmetric magnetic films of varying thickness. Crucially, we observe thickness-dependent transitions between the two states, with regions of metastability where both configurations coexist. We construct a phase diagram detailing the parameter space for their existence and transitions, provide an effective description of the interactions that mediate the transition, and discuss the implications of this type of state switching.