Magneto-Optical Kerr Effect, Enhanced by the Plasma Resonance of Charge Carriers

It is shown by model calculations that the dispersion of the diagonal part of the dielectric constant near the plasma edge in a metallic crystal has a strong influence on the magneto-optical properties. The plasma edge leads to resonancelike peaks in the Kerr rotation and Kerr ellipticity spectra and to a strong enhancement of the magnitude of the Kerr effect. The sharp and very large peaks observed in the Kerr effect of several transition-metal and rare-earth compounds are not necessarily related to sharp magneto-optical transitions, but could be a result of the presence of the plasma edge at the same frequenc