The microwave response of a two-dimensional (2D) electron system located on a dielectric ferromagnetic film, which in turn lies on a conducting metal (gate), has been theoretically studied. The entire system has been placed in an external static magnetic field. It has been found that the ferromagnetic resonance of the film and the cyclotron resonance of the electrons of the 2D system interact in the magnetic field, leading to their repulsion (“anticrossing”). It has been revealed that the anticrossing region is characterized not only by the modification of resonance frequencies compared to the cyclotron resonance in the 2D system without the ferromagnetic substrate and the ferromagnetic resonance in the film without the 2D system, but also by a strong change in the resonance linewidths.
Zabolotnykh et al. (Sun,) studied this question.