Suppression of the two-dimensional electron gas in LaGaO 3 /SrTiO 3 by cation intermixing

Abstract

Cation intermixing at the n-type polar LaGaO 3 /SrTiO 3 (001) interface is investigated by first principles calculations. Tiâ‡"Ga, Srâ‡"La, and SrTiâ‡"LaGa intermixing are studied in comparison to each other, with a focus on the interface stability. We demonstrate in which cases intermixing is energetically favorable as compared to a clean interface. A depopulation of the Ti 3d xy orbitals under cation intermixing is found, reflecting a complete suppression of the two-dimensional electron gas present at the clean interface.