Termination control of electronic phases in oxide thin films and interfaces: LaAlO3/SrTiO3(001)

TL;DR

This paper reviews how first principles calculations reveal the mechanisms behind the electronic properties and phase behaviors of LaAlO3/SrTiO3(001) thin films, including tunability and coexistence of magnetism and superconductivity.

Contribution

It provides a comprehensive analysis of the factors influencing electronic phases in LaAlO3/SrTiO3 interfaces, highlighting the effects of termination, thickness, and external modifications.

Findings

Electronic properties depend strongly on surface and interface termination.

Film thickness and defects significantly influence electronic behavior.

External layers and contacts can tune the system's electronic phases.

Abstract

A wealth of intriguing properties emerge in the seemingly simple system composed of the band insulators LaAlO3 and SrTiO3 such as a two-dimensional electron gas, superconductivity and magnetism. In this paper we review the current insight obtained from first principles calculations on the mechanisms governing the behavior of thin LaAlO3 films on SrTiO3(001). In particular, we explore the strong dependence of the electronic properties on the surface and interface termination, the finite film thickness, lattice polarization and defects. A further aspect that is addressed is how the electronic behavior and functionality can be tuned by a SrTiO3 capping layer, adsorbates and metallic contacts. Lastly, we discuss recent reports on the coexistence of magnetism and superconductivity in this system for what they might imply about the electronic structure of this system.