Kerr Rotation and Magnetic Circular Dichroism Spectraof Ferromagnetic InMnSb and InMnAs

摘要

Magnetooptical Kerr rotation and magnetic circular dichroism (MCD) have been measured in thin epitaxial layers of the narrow gap ferromagnetic semiconductors InMnSb and InMnAs grown by low-temperature molecular beam epitaxy. The measurements were carried out in the wavelength range from 400 to 7000 nm. The wavelength dependence of Kerr rotation and MCD were modelled using the same set of parameters. To calculate the Landau level energies for the above systems we have used a -model developed by Trebin et al. [1, 2] combined with an exchange matrix, as described by Rigaux [3]. Taking into account transition energies corresponding to the selection rules for right and left circularly polarized light enabled us to calculate both Kerr rotation and MCD using procedures described by Lang et al. [4] The fits yield values for the exchange parameters N₀α and N₀β.