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arXiv · 1309.2976

Dynamical control of orbital occupations via a ferroelectric-induced polar state in metallic manganites

Hanghui Chen·Qiao Qiao·Matthew S. J. Marshall·Alexandru B. Georgescu·Ahmet Gulec·Patrick J. Phillips·Robert F. Klie·Frederick J. Walker·Charles H. Ahn·Sohrab Ismail-Beigi
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Abstract

The breaking of orbital degeneracy on a transition metal cation and the resulting unequal electronic occupations of these orbitals provide a powerful lever over electron density and spin ordering in metal oxides. Here, we show how to dynamically modulate the orbital populations on Mn atoms at ferroelectric/manganite interfaces by switching the ferroelectric polarization. The change in orbital occupation can be as large as 10\%, greatly exceeding that of bulk manganites. This flippable orbital splitting is in large part controlled by the propagation of ferroelectric polar displacements into the interfacial region, a structural motif absent in the bulk and unique to the interface. We use {\it ab initio} theory, epitaxial thin film growth, and scanning transmission electron microscopy to verify the predicted interfacial polar state and concomitant orbital splittings.

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Hanghui Chen, Qiao Qiao, Matthew S. J. Marshall, Alexandru B. Georgescu, Ahmet Gulec, Patrick J. Phillips, Robert F. Klie, Frederick J. Walker, Charles H. Ahn, Sohrab Ismail-Beigi. 2013-09-11. Dynamical control of orbital occupations via a ferroelectric-induced polar state in metallic manganites. https://arxiv.org/abs/1309.2976

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