Resonant spin wave excitation in magnetoplasmonic bilayers using short laser pulses

Abstract

In magnetically ordered solids a static magnetic field can be generated by virtue of the transverse magneto-optical Kerr effect (TMOKE). Moreover, the latter was shown to be dramatically enhanced due to the optical excitation of surface plasmons in nanostructures with relatively small optical losses. In this paper we suggest a new method of resonant optical excitations in a prototypical bilayer composed of noble metal (Au) with grating and a ferromagnet thin film of yttrium iron garnet (YIG) via frequency comb. Based on magnetization dynamics simulations we show that for the frequency comb with the parameters, chosen in resonant with spin-wave excitations of YIG, TMOKE is drastically enhanced, hinting towards possible technological applications in the optical control of spintronics systems.

Transverse magneto-optical Kerr effect enhanced at the bound states in continuum

“…The systems of Eqs. (12,13) can be simplified by employing the linear approximation for ∆ 0,−1 (ω, θ) = δ 0,−1 (θ)[ω − ω 0,−1 (θ)] and constant approximation for the other parameters κ(ω, θ) = κ(ω ± −1 , θ), Γ 0 (ω, θ) = Γ 0 (ω ± 0 , θ). This approximation well describes reflection in the spectral range close to the resonance.…”

“…However, in traditional bulk metals magneto-optical effects are weak, and the reflectivity modulation is on the order of 10 −2 ÷10 −4 [2][3][4]. A promising alternative is to exploit the plasmonic resonances of the structure [5][6][7][8][9][10][11][12][13]. For instance, the TMOKE strength up to 1.5% has been demonstrated in the hybrid nanostructures where the magnetic material is placed near a metallic layer, supporting the surface plasmon resonance [7].…”