Angular dependence of hump-shape Hall Effects for distinguishing between Karplus-Luttinger and Topological Origins

Among various magnetic thin film heterostructures in solid state Physics, two contrasting mechanisms of the hump-shaped Hall Effects remain ambiguous and debated, namely the overlap of two opposite-signed Karplus-Luttinger Hall-loops associated with inhomogeneous collinear magnetic bubbles with perpendicular anisotropy, or the Topological/geometrical Hall Effect associated with magnetic skyrmions. Their similarity in topology imposes difficulty in discrimination via magnetic imaging. Here, this ambiguity is overcome by the divergence exponent of angle-dependent hump peak fields via magnetic field rotation characterization on several heterostructures. Their difference in sensitivity to in-plane fields reveals that the former mechanism involves higher uniaxial anisotropy than the latter, departing from the pure skyrmion regime described by Ginzburg-Landau framework of triple-q spin-wave superposition. Various materials can be collapsed into a single curve of divergence exponent versus domain wall energy, bridging the crossover of the two aforementioned mechanisms.
Comment: 6 Pages and 4 figures in the main text, 9 pages and 5 figures in the supplementary information