Localization of strongly correlated electrons as Jahn-Teller polarons in manganites

A realistic modeling of manganites should include the Coulomb repulsion between e(g) electrons, Hund's rule coupling to t(2g) spins, and Jahn-Teller phonons. Solving such a model by dynamical mean field theory, we report large magnetoresistances and spectra in good agreement with experiments. The physics of the unusual, insulatinglike paramagnetic phase is determined by correlated electrons which are-due to strong correlations-easily trapped as Jahn-Teller polarons.