Anomalous Influence of an External Magnetic Field on the Electron Energy Spectrum of Ferromagnetic Semiconductors with Strong p,d-hybridization

We investigate the influence of magnetic field on the optical conductivity and electron spectra of lanthanum manganites, which are used as magneto-optical switches. It has been shown that a narrow band of heavy fermions appears in the gap. The chemical potential is located in this band due to hole doping. For this reason, heavy fermions are responsible for the magnetism, optical properties and charge transfer. The scattering of heavy fermions by spin fluctuations and charge density fluctuations induced by them, lead to the Anderson localization. This effect determines the anomalous relationship between the magnetic and electron subsystems. The formulated model explains the observation and magnetorefractive magnetoresistive effects for identical values of temperatures and magnetic fields.