Exponential decay of relaxation effects at LaAlO3/SrTiO3 heterointerfaces

TL;DR

This study uses first-principles calculations to analyze how structural and electronic relaxation effects decay exponentially at LaAlO3/SrTiO3 heterointerfaces, revealing the spatial extent of interface-induced phenomena.

Contribution

It provides a quantitative analysis of the exponential decay of relaxation effects at the heterointerface using first-principles methods.

Findings

Relaxation effects extend over approximately two SrTiO3 unit cells.

Atomic displacements decay exponentially with distance from the interface.

Electronic states are confined to a region of about two unit cells.

Abstract

We study the decay of interface induced structural and electronic relaxation effects in epitaxial LaAlO3/SrTiO3 heterostructures. The results are based on first-principles band structure calculations for a multilayer configuration with an ultrathin LaAlO3 layer sandwiched between bulk-like SrTiO3 layers. We carry out the structure optimization for the heterointerface and investigate the electronic states of the conducting interface layer, which is found to extend over two SrTiO3 unit cells. The decay of atomic displacements is analyzed as a function of the distance to the interface, and the resulting exponential law is evaluated quantitatively.