Infrared magneto-optical properties of (III,Mn)V ferromagetic semiconductors

We present a theoretical study of the infrared magneto-optical properties of ferromagnetic (III,Mn)V semiconductors. Our analysis combines the kinetic exchange model for (III,Mn)V ferromagnetism with Kubo linear response theory and Born approximation estimates for the effect of disorder on the valence band quasiparticles. We predict a prominent feature in the ac-Hall conductivity at a frequency that varies over the range from 200 to 400 meV, depending on Mn and carrier densities, and is associated with transitions between heavy-hole and light-hole bands. In its zero frequency limit, our Hall conductivity reduces to the $\vec k$-space Berry's phase value predicted by a recent theory of the anomalous Hall effect that is able to account quantitatively for experiment. We compute theoretical estimates for magnetic circular dichroism, Faraday rotation, and Kerr effect parameters as a function of Mn concentration and free carrier density. The mid-infrared response feature is present in each of these magneto-optical effects.Comment: 11 pages, 5 figure

Analysis of magnetorefractive effect in La₀.₇Ca₀.₃MnO₃ thin films in the IR spectral range

We have reported the results of investigation of a magneto refractive effect on magnetoreflection and magnetotransmission modes in La₀.₇Ca₀.₃MnO₃ manganite thin films and crystals in the middle IR spectral range. The effects can reach several percents for single crystals and up to 20—40 % for thin films near Curie temperature. It was shown that the magnitude and spectra of the magnetorefractive effect strongly depend on magnetoresistance and optical properties of manganites. The overall qualitative agreement was obtained between the calculated in the framework of the effective medium approach data and experimental data