Orbital correlations in the ferromagnetic half-metal CrO2 - art. no. 214421

We deduce a model relevant for the description of the ferromagnetic half-me tal chromium dioxide (CrO2), widely used in magnetic recording technology. The model describes the effect of dynamical, local orbital correlations ari sing from local quantum chemistry of the material. A finite-temperature sol ution of the model in d = infinity provides a natural explanation of the op tical response, photoemission, resistivity, and the large Woods-Saxon ratio observed in experiments. Our study confirms the important role of many-bod y dynamical correlation effects for a proper understanding of the metallic phase of CrO2.