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arXiv · 1204.4711

Oxygen vacancies at titanate interfaces: two-dimensional magnetism and orbital reconstruction

N. Pavlenko·T. Kopp·E. Y. Tsymbal·J. Mannhart·G. A. Sawatzky
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Abstract

We show that oxygen vacancies at titanate interfaces induce a complex multiorbital reconstruction which involves a lowering of the local symmetry and an inversion of t2g and eg orbitals resulting in the occupation of the eg orbitals of Ti atoms neighboring the O vacancy. The orbital reconstruction depends strongly on the clustering of O vacancies and can be accompanied by a magnetic splitting between the local eg orbitals with lobes directed towards the vacancy and interface dxy orbitals. The reconstruction generates a two-dimensional interface magnetic state not observed in bulk SrTiO3. Using generalized gradient approximation (LSDA) with intra-atomic Coulomb repulsion (GGA+U), we find that this magnetic state is common for titanate surfaces and interfaces.

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N. Pavlenko, T. Kopp, E. Y. Tsymbal, J. Mannhart, G. A. Sawatzky. 2012-04-20. Oxygen vacancies at titanate interfaces: two-dimensional magnetism and orbital reconstruction. https://doi.org/10.1103/physrevb.86.064431

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