Microscopic understanding of the orbital splitting and its tuning at oxide interfaces
1 Institute of Solid State Physics, Vienna University of Technology - A-1040 Vienna, Austria, EU
2 Institut für Theoretische Physik und Astrophysik, Universität Würzburg Am Hubland, D-97074 Würzburg, Germany, EU
Received: 15 June 2012
Accepted: 13 July 2012
By means of a Wannier projection within the framework of density functional theory, we are able to identify the modified c-axis hopping and the energy mismatch between the cation bands as the main source of the t2g splitting around the Γ-point for oxide heterostructures, excluding previously proposed mechanisms such as Jahn-Teller distortions or electric-field asymmetries. Interfacing LaAlO3, LaVO3, SrVO3 and SrNbO3 with SrTiO3 we show how to tune this orbital splitting, designing heterostructures with more dxy electrons at the interface. Such an “orbital engineering” is the key for controlling the physical properties at the interface of oxide heterostructures.
PACS: 73.20.-r – Electron states at surfaces and interfaces / 73.21.-b – Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems / 79.60.Jv – Interfaces; heterostructures; nanostructures
© EPLA, 2012