Unified theory of phase separation and charge ordering in doped manganite perovskites

Abstract

A unified theory is developed to explain various types of electronic collective behaviors in doped manganites R${}_{1-x}$X${}_x$MnO${}_3$ (R = La, Pr,Nd etc. and X = Ca, Sr, Ba etc.). Starting from a realistic electronic model, we derive an effective Hamiltonianis by ultilizing the projection perturbation techniques and develop a spin-charge-orbital coherent state theory, in which the Jahn-Teller effect and the orbital degeneracy of e${}_g$ electrons in Mn ions are taken into account. Physically, the experimentally observed charge ordering state and electronic phase separation are two macroscopic quantum phenomena with opposite physical mechanisms, and their physical origins are elucidated in this theory. Interplay of the Jahn-Teller effect, the lattice distortion as well as the double exchange mechanism leads to different magnetic structures and to different charge ordering patterns and phase separation.

10 ReVTEX pages with 4 figures attached

References in corpus (9)

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• Current-induced Spin Polarization in Two-Dimensional Hole Gas
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• Coloumb interaction and instability of CE-structure in half doped manganites
• Effective spinless fermions in the strong coupling Kondo model
• Topological quantum phase transition and the Berry phase near the Fermi surface in hole-doped quantum wells
• Gate fidelity comparison in semiconducting spin qubit implementations affected by control noises
• Spin current in the Kondo lattice model
• Semiconducting double-dot exchange-only qubit dynamics in presence of magnetic and charge noises
• Curie temperature of the two band double exchange model for manganites
• Aspects of the FM Kondo Model: From Unbiased MC Simulations to Back-of-an-Envelope Explanations