Analysis of Electronic and Structural Properties of Surfaces and Interfaces Based on LaAlO3 and SrTiO3

摘要

Recently, it was established that a two-dimensional electron system can arise at the interface between two oxide insulators LaAlO and SrTiO. This paradigmatic example exhibits metallic behaviors and magnetic properties between non-magnetic and insulating oxides. Despite a huge amount of theoretical and experimental work a thorough understanding is yet to be achieved. We analyzed the structural deformations of a LaAlO (001) slab induced by hydrogen adatoms and oxygen vacancies at its surface by means of density functional theory. Moreover, we investigated the influence of surface reconstruction on the density of states and determined the change of the local density of states at the Fermi level with increasing distance from the surface for bare LaAlO and for a conducting LaAlO/SrTiO interface. In addition, the Al-atom displacements and distortions of the TiO-octahedra were estimated.