Dual Tuning of Doubly Hybridized Spin-Electromagnetic Waves in All-Thin-Film Multiferroic Multilayers

Theoretical investigation of dual (electric and magnetic) tuning of dispersion characteristics has been studied for the doubly hybridized spin-electromagnetic waves (SEWs) propagating perpendicularly to the direction of static magnetization in tangentially magnetized all-thin-film multiferroic multilayers. The multilayers consisted of two thin ferrite films separated by a thin ferroelectric film. The SEW spectrum was formed as the result of the double hybridization among one electromagnetic mode and two spin-wave modes. Such hybridization took place if the initial dispersion characteristics of these modes were degenerated. The electric tuning was realized owing to the changing of the magneto-dipole interaction between the magnetic films caused by a variation of dielectric constant of the ferroelectric film. It was shown that a decrease in permittivity of the ferroelectric film of micrometer thickness by a factor of two induces change of the SEW wavenumber up to tens of radian per centimeter.