Double-Exchange Model: Phase Diagram at Zero-Temperature
  The analytical zero-temperature phase diagram of the double exchange model for classical background spins as a function of the carrier density and Hund's coupling in the entire range of these parameters is presented. By constructing a continuum field theory we explore the possibility of a continuous phase transition from ferromagnetic state to a gently varying textured state. We find such a transition in and below two dimensions and show that the emerging stable state is a spin-spiral which survives the tendency towards phase separation into commonly considered phases, and is also energetically favored to the canted state, for low carrier density. 
David Pekker, Swagatam Mukhopadhyay, Nandini Trivedi, and Paul M.   Goldbart