ENHANCEMENT OF THE MAGNETOOPTICAL KERR ROTATION IN NONLINEAR-OPTICAL RESPONSE

Using an electronic theory we calculate the magneto-optical Kerr rotat ion in Second-Harmonic Generation (SHG). We derive Fresnel's formulas for the nonlinear optical response. Mathematical details of the deriva tion are given. For the longitudinal and polar Kerr configuration and for arbitrary angles of incidence it is found that the Kerr angle in S HG may be enhanced by up to one order of magnitude compared to the lin ear Kerr angle. This enhancement is caused by interband and intraband transitions (plasmons) which in the linear case suppress the Kerr rota tion in the optical range. Our results will be useful for a microscopi c study of 2D magnetism.