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Orbital ordering in LaMnO$_3$: Electron-electron versus electron-lattice interactions

Wei-Guo Yin·Dmitri Volja·Wei Ku
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Abstract

The relative importance of electron-lattice (e-l) and electron-electron (e-e) interactions in ordering orbitals in LaMnO$_3$ is systematically examined within the LDA+$U$ approximation of density functional theory. A realistic effective Hamiltonian is derived from novel Wannier functions analysis of the electronic structure. Surprisingly, e-l interaction ($\simeq 0.9$ eV) alone is found insufficient to stabilize the orbital ordered state. On the other hand, e-e interaction ($\simeq 1.7$ eV) not only induces orbital ordering, but also greatly facilitates the Jahn-Teller distortion via enhanced localization. Further experimental means to quantify the competition between these two mechanisms are proposed.

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Wei-Guo Yin, Dmitri Volja, Wei Ku. 2006-02-16. Orbital ordering in LaMnO$_3$: Electron-electron versus electron-lattice interactions. https://doi.org/10.1103/physrevlett.96.116405

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