Magnetic, charge and orbital orderings in manganites

Abstract

We develop a theory to understand various types of electronic collective behaviors in manganites, such as magnetic, charge, and orbital orderings. Starting from an electronic model with strong correlations, we derive an effective Hamiltonian by utilizing the projection perturbation techniques, in which the orbital degeneracy of e g electrons in Mn ions are taken into account. Interplay of spin, charge and orbital degree of freedom leads to different magnetic and electronic structures in manganites.