In this paper we develop the excitonic theory of 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 two in the case of MoS2 in proximity to a Cobalt thin film.
@article{arxiv.2001.00270,
title = {Excitonic Magneto-Optical Kerr Effect in 2D Transition Metal Dichalcogenides Induced by Spin Proximity},
author = {J. C. G. Henriques and G. Catarina and A. T. Costa and J. Fernández-Rossier and N. M. R. Peres},
journal= {arXiv preprint arXiv:2001.00270},
year = {2020}
}