Energetics of Ising-vortex interactions in La_0.7Sr_0.3MnO₃ brickwork artificial spin ices

Understanding how spin texture formation can be engineered is essential for the design and development of spin-based memory and computing devices. Arrays of interacting nanomagnets called artificial spin ices (ASIs) offer a route towards understanding how dipolar interactions can influence the formation of different spin texture states. Using micromagnetic simulations, we studied La_0.7Sr_0.3MnO₃-based brickwork ASIs and showed that the formation of single and double vortices, which we collectively term as complex spin textures (CSTs), depends on the magnetization of the nearest-neighboring nanoislands. Micromagnetic simulations of isolated nanoislands reveal that the tips of CST-bearing nanoislands behave as effective dipoles, thus allowing interactions between CSTs and single domains to be interpreted within an Ising dipolar interaction framework. Through an energy analysis of interacting nanoisland sets, we find that the magnetic configuration of nearest-neighboring nanoislands can induce energy splitting between the two chiralities of a single- or double-vortex state. Moreover, we find that this energy splitting can be predicted by comparing the number of attracting dipolar interactions each chiral state produces. These results can allow us to predict the appearance of a CST in an ASI, which can be leveraged towards developing new ASI systems capable of exploiting CST and Ising states.