Optically excited multi-band conduction in LaAlO3/SrTiO3 heterostructures

Abstract

The low-temperature resistance of a conducting LaAlO3/SrTiO3 interface with a 10 nm thick LaAlO3 film decreases by more than 50% after illumination with light of energy higher than the SrTiO3 band-gap. We explain our observations by optical excitation of an additional high mobility electron channel, which is spatially separated from the photo-excited holes. After illumination, we measure a strongly non-linear Hall resistance which is governed by the concentration and mobility of the photo-excited carriers. This can be explained within a two-carrier model where illumination creates a high-mobility electron channel in addition to a low-mobility electron channel which exists before illumination.

arXiv comment4 pages, 3 figures

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Cited by in corpus (9)

• Growth-induced electron mobility enhancement at the LaAlO${}_3$/SrTiO${}_3$ interface
• Thermally excited multi-band conduction in LaAlO3/SrTiO3 heterostructures exhibiting magnetic scattering
• The mechanism of spin-orbit coupling in a 2D oxide interface
• Infrared study of the quasi-two-dimensional electron system at the interface between SrTiO${}_3$ and crystalline or amorphous LaAlO${}_3$
• Transport and thermoelectric properties of the LaAlO${}_3$/SrTiO${}_3$ interface
• Conducting and insulating LaAlO${}_3$/SrTiO${}_3$ interfaces: A comparative surface photovoltage investigation
• Quantum oscillations in an optically-illuminated two-dimensional electron system at the LaAlO${}_3$/SrTiO${}_3$ interface
• Understanding the onset of negative electronic compressibility in one- and two-band 2D electron gases: Application to LaAlO${}_3$/SrTiO${}_3$
• Manipulating electronic states at oxide interfaces using focused micro X-rays from standard lab-sources