Wednesday, November 21, 2012

1211.4778 (V. K. Guduru et al.)

Optically excited multi-band conduction in LaAlO3/SrTiO3
heterostructures
   [PDF]

V. K. Guduru, A. Granados del Aguila, S. Wenderich, M. K. Kruize, A. McCollam, P. C. M. Christianen, U. Zeitler, A. Brinkman, G. Rijnders, H. Hilgenkamp, J. C. Maan
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.
View original: http://arxiv.org/abs/1211.4778

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