Speaker
Description
We present analysis of microscopic origin of magneto-optical spectra from the electronic
structure of bcc Fe. The magneto-optical (MO) permittivity spectra are obtained by the
WIEN2k code and compared to the corresponding experimental MO Kerr effect spectra. The
ab-initio spectra are given by the Kubo formula, i.e., as a result of summation over all pairs of
electronic bands and integration over the Brillouin zone that all sum up to the single MO
spectrum. We investigate what features of electronic structure contribute to the outgoing total
MO spectrum. We have also developed several novel ways of visualizing MO-related
phenomena in the Brillouin zone.
It turns out that strong MO signal comes from several isolated k-points in the Brillouin zone,
where the band degeneracy is avoided by the spin-orbit interaction. There are two major types
of MO contributions determined by the nature of the avoided degeneracy (given by topology
of the approaching bands), that contribute differently to the total MO spectrum. Both types are
visualized and their contributions to the total spectrum are demonstrated in the form of local
MO spectra.
