Optical and magneto-optical response of half-metallic manganites

Motivated by the recent optical and magneto-optical measurements on half-metallic ferromagnetic three-dimensional manganites, we combine a tight-binding fit of the one-particle bandstructure with the dynamical mean-field theory, which treats the dynamical orbital correlations and the combination of Jahn-Teller and doping-induced disorder on the same footing. We show how all of the above effects are necessary to obtain good semiquantitative agreement with experimental features. As applications, we show how modest external magnetic fields drive drastic changes in the (B1g) electronic Raman scattering lineshape, optical and magneto-optical spectra, demonstrating the colossal magnetoconductivity reported earlier. Good semiquantitative agreement with published experimental work is found, providing strong evidence for dynamical multi-orbital electronic correlations even in the well-doped half-metallic ferromagnetic state in CMR manganites