Lateral semiconductor magnonics: an array of GaAs stripes atop the YIG layer

Abstract

In this work, we demonstrate the numerical and experimental research of the spin-wave transport in a structure composed of a gallium arsenide (GaAs) stripe lattice interfaced to an yttrium iron garnet layer. We show that this structure can be considered as an array of an infinite number of laterally coupled ferrite-semiconductor waveguides. We show that the surface wave properties for colinear propagation along the semiconductor stripes are similar to the waves in magnetic films with partial metallization. In addition, the properties of these surface waves depend on the electron concentration of the GaAs and thus may be tuned. With regard to the wave propagation at a certain angle to the GaAs stripe lattice, the Bragg resonance forms and the corresponding band gap depend on the angle between the wave to the stripes and on the GaAs electron density. The Brillouin light scattering technique was used to experimentally observe the spin-wave beam transformation, and microwave measurements support the numerical data and reveal the mechanism of the dip formation and widening of the frequency range in the spin-wave transmission. The proposed structure could be used as a reconfigurable metasurface and magnonic beam separation unit.