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arXiv · 0808.4025

Interplay of frustration, magnetism, charge ordering, and covalency in a model of Na0.5CoO2

Jaime Merino·B. J. Powell·Ross H. McKenzie
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Abstract

We investigate an effective Hamiltonian for Na0.5CoO2 that includes the electrostatic potential due to the ordered Na ions and strong electronic correlations. This model displays a subtle interplay between metallic and insulating phases and between charge and magnetic order. For realistic parameters, the model predicts an insulating phase with similarities to a covalent insulator. We show that this interpretation gives a consistent explanation of experiments on Na0.5CoO2, including the small degree of charge ordering, the small charge gap, the large moment, and the optical conductivity.

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Jaime Merino, B. J. Powell, Ross H. McKenzie. 2009-01-19. Interplay of frustration, magnetism, charge ordering, and covalency in a model of Na0.5CoO2. https://doi.org/10.1103/physrevb.79.161103

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