The experimental observation that vanadate superlattices (LaVO 3)m/SrVO3 show ferromagnetism up to room temperature (Lüders U. et al., Phys. Rev. B, 80 (2009) 241102(R)) is investigated by means of density functional theory, and the band structure for m = 5 and 6 is calculated. A buckling of the interface VO2 layers is found in both cases, but subtle differences in bond length lead to very different properties for even and odd values of m: in the even case, the two interface VO2 layers effectively decouple from the adjacent LaO layers due to a strong bond length enhancement. This results into a local inversion of the orbital occupancy and to the confinement of the charge carriers. In the odd case, the amplitude of the bond length variation is smaller, so that the charge carriers spill into the deeper-lying VO2 layers, and spin-polarised interfaces are obtained. © Copyright EPLA, 2013.
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: We thank S. NAZIR and T. KOPP for valuable discussions. Financial support by the German Research Foundation within TRR 80 (CS) and by the ANR through GeCoDo-ANR-2011-JS0800101 (UL and RF) is acknowledged. UL and RF thank the Region Basse-Normandie and the Ministere de la Recherche for financial support.
ASJC Scopus subject areas
- Physics and Astronomy(all)