Faraday and Kerr rotation due to photoinduced orbital magnetization in two-dimensional electron gas

Abstract

We study theoretically the Faraday and Kerr rotation of a probe field due to the orbital magnetization of a two-dimensional electron gas induced by a circularly polarized pump. We develop a microscopic theory of these effects in the intraband spectral range based on the analytical solution of the kinetic equation for linear and parabolic energy dispersion of electrons and arbitrary scattering potential. We show that the spectral dependence of rotation angles and accompanying ellipticities experiences a sharp resonance when the probe and pump frequencies are close to each other. At the resonance, the Faraday and Kerr rotation angles are of the order of $0.1^\circ$ per 1~kW/cm$^2$ of the pump intensity in graphene samples, corresponding to a pump-induced synthetic magnetic field of about 0.1~T. We also analyze the influence of the dielectric contrast between dielectric media surrounding the two-dimensional electron gas on the rotation angles.