Growth-induced electron mobility enhancement at the LaAlO${}_3$/SrTiO${}_3$ interface

Abstract

We have studied the electronic properties of the 2D electron liquid present at the LaAlO${}_3$/SrTiO${}_3$ interface in series of samples prepared at different growth temperatures. We observe that interfaces fabricated at 650°C exhibit the highest low temperature mobility ($\approx 10000{\text{ cm}}^2/\text{Vs}$) and the lowest sheet carrier density ($\approx 5\times 10^{12}{\text{ cm}}^{-2}$). These samples show metallic behavior and Shubnikov-de Haas oscillations in their magnetoresistance. Samples grown at higher temperatures (800-900°C) display carrier densities in the range of $\approx 2-5\times 10^{13}{\text{ cm}}^{-2}$ and mobilities of $\approx 1000{\text{ cm}}^2/\text{Vs}$ at 4K. Reducing their carrier density by field effect to $8\times 10^{12}{\text{ cm}}^{-2}$ lowers their mobilites to $\approx 50{\text{ cm}}^2/\text{Vs}$ bringing the conductance to the weak-localization regime.

References in corpus (4)

• Electric Field Control of the LaAlO${}_3$/SrTiO${}_3$ Interface Ground State
• Surface defects and conduction in polar oxide heterostructures
• Large modulation of the Shubnikov-de Haas oscillations by the Rashba interaction at the LaAlO${}_3$/SrTiO${}_3$ interface
• Optically excited multi-band conduction in LaAlO3/SrTiO3 heterostructures

Cited by in corpus (1)

• Oxide 2D electron gases as a route for high carrier densities on (001) Si