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Competing Ferromagnetic and Charge-Ordered States in Models for Manganites: the Origin of the CMR Effect

Cengiz Sen·Gonzalo Alvarez·Elbio Dagotto
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Abstract

The one-orbital model for manganites with cooperative phonons and superexchange coupling $J_{\rm AF}$ has been investigated via large-scale Monte Carlo (MC) simulations. Results for two-orbitals are also briefly discussed. Focusing on electronic density $n$=0.75, a regime of competition between ferromagnetic (FM) metallic and charge-ordered (CO) insulating states was identified. In the vicinity of the associated bicritical point, colossal magnetoresistance (CMR) effects were observed. The CMR is associated with the development of short-distance correlations among polarons, above the spin ordering temperatures, resembling the charge arrangement of the low-temperature CO state.

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Cengiz Sen, Gonzalo Alvarez, Elbio Dagotto. 2007-02-19. Competing Ferromagnetic and Charge-Ordered States in Models for Manganites: the Origin of the CMR Effect. https://doi.org/10.1103/physrevlett.98.127202

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