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arXiv · 0812.4380

Magnetically induced electronic ferroelectricity in half-doped manganites

Gianluca Giovannetti·Sanjeev Kumar·Jeroen van den Brink·Silvia Picozzi
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Abstract

Using a joint approach of density functional theory and model calculations, we demonstrate that a prototypical charge ordered half-doped manganite, La$_{1/2}$Ca$_{1/2}$MnO$_3$ is multiferroic. The combination of a peculiar charge-orbital ordering and a tendency to form spin dimers breaks inversion symmetry, leads to a ferroelectric ground-state with a polarization up to several $\mu C/cm^2$. The presence of improper ferroelectricity does not depend on hotly debated structural details of this material: in the Zener-polaron structure we find a similar dramatic ferroelectric response with a large polarization of purely magnetic origin.

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Gianluca Giovannetti, Sanjeev Kumar, Jeroen van den Brink, Silvia Picozzi. 2008-12-23. Magnetically induced electronic ferroelectricity in half-doped manganites. https://doi.org/10.1103/physrevlett.103.037601

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