Spin wave wavevector up-conversion in Y-shaped Permalloy structures

Spin waves in micrometer-sized, patterned Y-shaped Permalloy structures were studied using micro-focus Brillouin light scattering (BLS) with a magnetic field applied in-plane. For in-plane magnetized thin films and microstrips, the dispersion relations depend on angle of magnetization respect to microstrip axis. BLS measurements show that spin generated two arms form top Y structure can be channeled into longer forms base when is oriented perpendicular long axis base. In this configuration, supports surface waves. A comparison data micromagnetic simulations reveals low-k by antenna are converted higher-k base, which may useful for nanomagnonic applications.