Quantum mechanics

Spin (aerodynamics)

Materials science

Ferromagnetism

Yttrium iron garnet

Spin wave

Semiconductor

Thermodynamics

Laser

Physics

Brillouin zone

Optics

Spin Hall effect

Condensed matter physics

Magnonics

Electron

Optoelectronics

Spin polarization

Gallium arsenide

Physical review. B./Physical review. B

We demonstrate laser-induced nonreciprocity of spin waves in the ferromagnetic-semiconductor structure. Surface spin waves in yttrium iron garnet film grown at the top of $n$-type gallium arsenide substrate were studied by means of Brillouin light-scattering spectroscopy. It is shown that spin-wave dispersion can be modified in a controlled manner by laser radiation. We observe the difference of up to 225 MHz when comparing the frequencies of counterpropagating spin waves. We attribute this frequency shift to the mutual influence of nonreciprocal spin-wave modal profiles and differences in magnetic anisotropies at two film surfaces as the result of laser-induced conductivity variation in GaAs substrate. We propose a simple model based on analytical dipole theory to describe the induced spin-wave nonreciprocity. Our results show the possibility of integration of magnonics and semiconductor electronics on the base of YIG/GaAs structures.

Route toward semiconductor magnonics: Light-induced spin-wave nonreciprocity in a YIG/GaAs structure