The Conducting Channel at the LaAlO${}_3$/SrTiO${}_3$ Interface

Abstract

Localization of electrons in the two-dimensional electron gas at the LaAlO${}_3$/SrTiO${}_3$ interface is investigated by varying the channel thickness in order to establish the nature of the conducting channel. Layers of SrTiO${}_3$ were grown on NdGaO${}_3$ (110) substrates and capped with LaAlO${}_3$. When the SrTiO${}_3$ thickness is $\le 6$ unit cells, most electrons at the interface are localized, but when the number of SrTiO${}_3$ layers is 8-16, the free carrier density approaches $3.3\times 10^{14}$ cm${}^{-2}$, the value corresponding to charge transfer of 0.5 electron per unit cell at the interface. The number of delocalized electrons decreases again when the SrTiO${}_3$ thickness is $\ge 20$ unit cells. The $\sim 4$ nm conducting channel is therefore located significantly below the interface. The results are explained in terms of Anderson localization and the position of the mobility edge with respect to the Fermi level.

Main: 19 pages, 4 figures Supplementary: 14 pages, 10 figures

References in corpus (9)

• Magnetic effects at the interface between nonmagnetic oxides
• Electric Field Control of the LaAlO${}_3$/SrTiO${}_3$ Interface Ground State
• Direct imaging of the coexistence of ferromagnetism and superconductivity at the LaAlO3/SrTiO3 interface
• Critical thickness for ferromagnetism in LaAlO3/SrTiO3 heterostructures
• Topological superconductivity in bilayer Rashba system
• Field-Effect Devices Utilizing LaAlO${}_3$-SrTiO${}_3$ Interfaces
• Strong electronic correlation and strain effects at the interfaces between polar and nonpolar complex oxides
• Localization of Two-dimensional Electron Gas in LaAlO3/SrTiO3 Heterostructures
• Atomically flat interface between a single-terminated LaAlO3 substrate and SrTiO3 thin film is insulating

Cited by in corpus (5)

• Giant Oscillating Thermopower at Oxide Interfaces
• Controlling Kondo-like Scattering at the SrTiO3-based Interfaces
• Bandgap Controlling of the Oxygen-Vacancy-Induced Two-Dimensional Electron Gas in SrTiO3
• High field magneto-transport in two-dimensional electron gas LaAlO3/SrTiO3
• Two-dimensional electron systems in perovskite oxide heterostructures: Role of the polarity-induced substitutional defects