Spin wave excitation and directional propagation in presence of magnetic charges in square artificial spin ice

Artificial spin ice is a special class of engineered lattice of highly shape anisotropic single domain magnetic nanostructures which is used as one of the model systems to study the spin ice behavior observed in pyrochlore oxides. The nanomagnets interact via dipolar interaction which results in correlated magnetization dynamics exhibiting macroscopic spin configuration states. Here, we exploit the interplay of underlying magnetic state and external bias field orientation to study controlled spin wave propagation in square Artificial Spin Ice (sASI) by performing detailed micromagnetic simulations. We report that careful selection of vertices with local magnetic charges can effectively direct the anisotropic spin wave in presence of an external field. Further, we explore the influence of local charges due to the excited state in even-coordinated vertices as well as uncompensated charges due to odd-coordinated vertices on spin wave behavior. Our studies suggest that there is no perceptible difference on spin wave dynamical behavior due to the origin of local magnetic charge in sASI. Our results of controlled and directional spin wave propagation in sASI system may be useful for low-power consumption based all magnonic on-chip devices.