Phase Diagram of Doped Manganates

TL;DR

This paper investigates the phase diagram of doped manganates using an extended double exchange model and Schwinger boson formalism, revealing the instability of the canted phase and mapping phase separation regions.

Contribution

It extends the double exchange model analysis with Schwinger bosons and demonstrates the instability of the canted phase in doped manganates.

Findings

Reproduces de Gennes' canted phase but finds it unstable

Maps phase separation regions in the phase diagram

Provides numerical solutions to mean field equations

Abstract

The phase diagram of doped manganate compounds La_{1-x}A_xMnO_3 (with divalent A) is studied. We analyze an extension of the double exchange model using the Schwinger boson formalism. Earlier work by de Gennes on the existence of a canted phase is reproduced, although this phase is shown to be unstable towards phase separation in a broad regime of physical interest. We numerically solve the model's mean field equations and plot its phase diagram.