Phonon polaritons in magnetoelectric multiferroics film: the possibility to drive surface modes using magnetic field

Abstract

In this paper, we report our numerical study of transverse mode phonon polaritons generated on magnetoelectric multiferroic films. The mathematical models of the dispersion relation for both surface and guided-wave modes were derived by solving the Maxwell equations. Then, numerical calculations were performed for various thicknesses using parameters suitable for illustrating magnetoelectric multiferroic BaMnF4. It was found that around the thicknesses of 0.1 mm–1 mm, the guided-wave modes were discreet. The surface phonon polaritons were obtained at the region between ferroelectric resonant frequency ω e and intercept frequency ω i. These surface modes were reciprocal, i.e., ω( k ) = ω(− k ). These results were in good agreement with the calculated attenuated total reflection spectra. It was also found numerically that the application of a magnetic field was able to shift the frequency of the surface phonon polaritons.