Fine structure of phase separation in double-exchange systems

We present the fine structures of various phase separations (PS) in the double-exchange (DE) model either with or without antiferromagnetic (AF) superexchange coupling between localized spins in the framework of dynamical mean-field theory. They constitute a complete and unified description of stable, metastable, and unstable states near PS. At mean-field level, the PS between ferromagnetic (FM) and paramagnetic phases at low temperature in the DE model and that between FM and AF phases in the DE model with AF superexchange background are found stable against nearest-neighbor Coulomb repulsion. The relevance of our results to experiments and to other theoretical studies of PS is discussed.