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arXiv · 0710.1395

Mapping the Spatial Distribution of Charge Carriers in LaAlO3/SrTiO3 Heterostructures

M. Basletic·J. -L. Maurice·C. Carretero·G. Herranz·O. Copie·M. Bibes·E. Jacquet·K. Bouzehouane·S. Fusil·A. Barthelemy
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Abstract

At the interface between complex insulating oxides, novel phases with interesting properties may occur, such as the metallic state reported in the LaAlO3/SrTiO3 system. While this state has been predicted and reported to be confined at the interface, some works indicate a much broader spatial extension, thereby questioning its origin. Here we provide for the first time a direct determination of the carrier density profile of this system through resistance profile mappings collected in cross-section LaAlO3/SrTiO3 samples with a conducting-tip atomic force microscope (CT-AFM). We find that, depending upon specific growth protocols, the spatial extension of the high-mobility electron gas can be varied from hundreds of microns into SrTiO3 to a few nanometers next to the LaAlO3/SrTiO3 interface. Our results emphasize the potential of CT-AFM as a novel tool to characterize complex oxide interfaces and provide us with a definitive and conclusive way to reconcile the body of experimental data in this system.

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M. Basletic, J. -L. Maurice, C. Carretero, G. Herranz, O. Copie, M. Bibes, E. Jacquet, K. Bouzehouane, S. Fusil, A. Barthelemy. 2007-10-07. Mapping the Spatial Distribution of Charge Carriers in LaAlO3/SrTiO3 Heterostructures. https://doi.org/10.1038/nmat2223

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