ИСТИНА

Recently, it has been reported the novel concept of the magnetoplasmonic nanostructures with spatial symmetry breaking. In such structures the intensity magneto-optical response in transmittance experiences a non-zero modulation even at the normal incidence of light when the external magnetic field is applied in the transverse direction. We address the metal plasmonic nanostructure deposited on top of the magnetic layer has a spatial symmetry breaking. The unit cell of the plasmonic grating is spatially non-symmetric along the alternating direction of the grating cells. Thus, the symmetry of the structure is violated with respect to the rotation of the 180 degrees around the normal to the nanostructure. In other words, the asymmetry vector is directed along with the periodicity of the metal plasmonic structure. The surface plasmon polaritons (SPPs) excited at the [metal]/[magnetic dielectric] interface of the addressed structure experience the different conditions for the modes running forward and backward. This nonequivalence of two SPP modes propagating in opposite directions emerges due to the asymmetry of the addressed magnetoplasmonic nanostructure. The excitation of the spin waves in the magnetic layer of the nanostructure leads to the modulation of its magnetization. As a result, the magneto-optical response of the magnetoplasmonic nanostructure is also dependent on the excitation of the spin waves. We analyze by numerical simulations the mutual influence of the spin waves dynamics and the asymmetry properties of the magnetoplasmonic nanostructure. The features of the magneto-optical intensity effect in transmittance are discussed.