Excitonic magneto-optical Kerr effect in two-dimensional transition metal dichalcogenides induced by spin proximity
J. C. G. Henriques, Gonçalo Catarina, A. T. Costa, J. Fernández‐Rossier, N. M. R. Peres
Abstract
In this paper, we develop the excitonic theory of the Kerr rotation angle in a two-dimensional (2D) transition metal dichalcogenide at zero magnetic field. The finite Kerr angle is induced by the interplay between spin-orbit splitting and proximity exchange coupling due to the presence of a ferromagnet. We compare the excitonic effect with the single-particle theory approach. We show that the excitonic properties of the 2D material lead to a dramatic change in the frequency dependence of the optical response function. We also find that the excitonic corrections enhance the optical response by a factor of 2 in the case of ${\mathrm{MoS}}_{2}$ in proximity to a cobalt thin film.