Coexisting mechanisms of thermally driven magnetization reversal in shakti spin ice systems

The switching mechanisms in artificial spin ice systems are investigated with focus on shakti and vertex-modified shakti lattices. Minimum energy paths are calculated using the geodesic nudged elastic band method implemented with a micromagnetic description of the system, including the internal magnetic structure of the islands and edge deviations. Two switching mechanisms, uniform magnetization rotation and domain wall formation, are found to have comparable activation energies. The preference for one over the other depends strongly on the saturation magnetization and the magnetic ordering of neighboring islands. Surprisingly, these mechanisms can coexist, leading to an enhanced probability of magnetization reversal. These results provide valuable insight that can help control internal magnetization switching processes in spin ice systems and help predict their thermodynamic properties.