Electronic structure and magneto-optical Kerr effect in La monochalcogenides

Abstract

The optical and magneto-optical (MO) spectra of the lanthanum monochalcogenides are investigated theoretically using the fully relativistic Dirac LMTO band-structure method. The LSDA calculations with shifted La 4f empty states describe quite well the shape and magnitude of the LaS MO spectra in an external magnetic field and to a lesser extent the MO spectra of LaSe. On the other hand, theory fails to describe the broader spectral structures in LaTe between 3 and 5 eV. The origin of the Kerr rotation in these compounds is examined.