Charge and spin ordering in perovskite manganites

Abstract

A magnetic phase diagram of the ground state of perovskite manganites is studied in a mean field approximation by putting emphasis on the coupling of charge and spin degrees of freedom. It is shown that a characteristic feature of the ground state observed near the quarter-filling can be reproduced, that is, the charge ordered state with a spin spiral ordering appears, being nearly degenerate with the fully polarized ferromagnetic state. Coupling of orbital and charge degrees of freedom and the electronic phase separation are also examined.