Laser-induced magnonic band gap formation and control in YIG/GaAs heterostructure

TL;DR

This study demonstrates how laser radiation can control spin-wave transport and magnonic band gaps in YIG/GaAs heterostructures, enabling integration of magnonics with semiconductor electronics.

Contribution

It introduces a method to optically tune magnonic band gaps and nonreciprocity in YIG/GaAs heterostructures through laser-induced charge carrier modulation.

Findings

Laser radiation induces and controls magnonic gaps.

Charge carrier variation affects spin-wave nonreciprocity.

Magnetic and electronic properties can be integrated via optical control.

Abstract

We demonstrate the laser-induced control over spin-wave (SW) transport in the magnonic crystal (MC) waveguide formed from the semiconductor slab placed on the ferrite film. We considered bilayer MC with periodical grooves performed on the top of the n-type gallium arsenide slab side that oriented to the yttrium iron garnet film. To observe the appearance of magnonic gap induced by laser radiation, the fabricated structure was studied by the use of microwave spectroscopy and Brillouin light-scattering. We perform detailed numerical studies of this structure. We showed that the optical control of the magnonic gaps (frequency width and position) is related to the variation of the charge carriers' concentration in GaAs. We attribute these to nonreciprocity of SW transport in the layered structure. Nonreciprocity was induced by the laser exposure of the GaAs slab due to SWs' induced electromagnetic field screening by the optically-generated charge carriers. We showed that SW dispersion, nonreciprocity, and magnonic band gap position and width in the ferrite-semiconductor magnonic crystal can be modified in a controlled manner by laser radiation. Our results show the possibility of the integration of magnonics and semiconductor electronics on the base of YIG/GaAs structures.