High Mobility in LaAlO3/SrTiO3 Heterostructures: Origin, Dimensionality and Perspectives

Abstract

We have investigated the dimensionality and origin of the magnetotransport properties of LaAlO3 films epitaxially grown on TiO2-terminated SrTiO3(001) substrates. High mobility conduction is observed at low deposition oxygen pressures (PO2 < 10^-5 mbar) and has a three-dimensional character. However, at higher PO2 the conduction is dramatically suppressed and nonmetallic behavior appears. Experimental data strongly support an interpretation of these properties based on the creation of oxygen vacancies in the SrTiO3 substrates during the growth of the LaAlO3 layer. When grown on SrTiO3 substrates at low PO2, other oxides generate the same high mobility as LaAlO3 films. This opens interesting prospects for all-oxide electronics.

4 pages, 4 figures. Accepted for publication in Phys. Rev. Lett

References in corpus (2)

• Origin of charge density at LaAlO3-on-SrTiO3 hetero-interfaces; possibility of intrinsic doping
• Low temperature metallic state induced by electrostatic carrier doping of SrTiO${}_3$

Cited by in corpus (12)

• Electric Field Control of the LaAlO${}_3$/SrTiO${}_3$ Interface Ground State
• Origin of Metallic States at Heterointerface between Band Insulators LaAlO${}_3$ and SrTiO${}_3$
• Electronic structure induced reconstruction and magnetic ordering at the LaAlO${}_3|$SrTiO${}_3$ interface
• Optical Study of the Free Carrier Response of LaTiO3/SrTiO3 Superlattices
• Anomalously large measured thermoelectric power factor in Sr${}_{1-x}$La${}_x$TiO${}_3$ thin films due to SrTiO${}_3$ substrate reduction
• Fundamental asymmetry in interfacial electronic reconstruction between insulating oxides
• Depth-Resolved Subsurface Defects in Chemically Etched SrTiO3
• Exponential decay of relaxation effects at LaAlO3/SrTiO3 heterointerfaces
• Electron energy loss spectroscopy determination of Ti oxidation state at the (001) LaAlO3/SrTiO3 interface as a function of LaAlO3 growth conditions
• Electronic structure of the SrTiO${}_3$/LaAlO${}_3$ interface revealed by resonant soft x-ray scattering
• Relaxation of transport properties in electron doped SrTiO3
• Oxide tunnel junctions supporting a two-dimensional electron gas