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arXiv · 1404.7705

Dual nature of the ferroelectric and metallic state in LiOsO$_3$

Gianluca Giovannetti·Massimo Capone
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Abstract

Using density functional theory we investigate the lattice instability and electronic structure of recently discovered ferroelectric metal LiOsO$_3$. We show that the ferroelectric-like lattice instability is related to the Li-O distortion modes while the Os-O displacements change the d-p hybridization as in common ferroelectric insulators. Within the manifold of the d-orbitals, a dual behavior emerges. The ferroelectric transition is indeed mainly associated to the nominally empty e$_g$ orbitals which are hybridized with the oxygen p orbitals, while the t$_{2g}$ orbitals are responsible of the metallic response. Interestingly, these orbitals are nominally half-filled by three electrons, a configuration which suffers from strong correlation effects even for moderate values of the screened Coulomb interaction.

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Gianluca Giovannetti, Massimo Capone. 2014-04-30. Dual nature of the ferroelectric and metallic state in LiOsO$_3$. https://doi.org/10.1103/physrevb.90.195113

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