Fabricating Superconducting Interfaces between Artificially-Grown LaAlO${}_3$ and SrTiO${}_3$ Thin Films

Abstract

Realization of a fully metallic two-dimensional electron gas at the interface between artificially-grown LaAlO${}_3$ and SrTiO${}_3$ thin films has been an exciting challenge. Here we present for the first time the successful realization of a superconducting 2DEG at interfaces between artificially-grown LaAlO${}_3$ and SrTiO${}_3$ thin films. Our results highlight the importance of two factors-the growth temperature and the SrTiO${}_3$ termination. We use local friction force microscopy and transport measurements to determine that in normal growth conditions the absence of a robust metallic state at low temperature in the artificially-grown LaAlO${}_3$/SrTiO${}_3$ interface is due to the nanoscale SrO segregation occurring on the SrTiO${}_3$ film surface during the growth and the associated defects in the SrTiO${}_3$ film. By adopting an extremely high SrTiO${}_3$ growth temperature, we demonstrate a way to realize metallic, down to the lowest temperature, and superconducting 2DEG at interfaces between LaAlO${}_3$ layers and artificially-grown SrTiO${}_3$ thin films. This study paves the way to the realization of functional LaAlO${}_3$/SrTiO${}_3$ superlattices and/or artificial LaAlO${}_3$/SrTiO${}_3$ interfaces on other substrates.

References in corpus (3)

• Electric Field Control of the LaAlO${}_3$/SrTiO${}_3$ Interface Ground State
• Growth mode control of the free carrier density in SrTiO3-d films
• Nature of weak magnetism in SrTiO3/LaAlO3 multilayers

Cited by in corpus (4)

• Bandgap Controlling of the Oxygen-Vacancy-Induced Two-Dimensional Electron Gas in SrTiO3
• An efficient and reliable growth method for epitaxial complex oxide films by molecular beam epitaxy
• A two-dimensional electron gas based on a 5s oxide with high room-temperature mobility and strain sensitivity
• Sequential pulsed laser deposition of homoepitaxial SrTiO${}_3$ thin films