Optically excited multi-band conduction in LaAlO3/SrTiO3   heterostructures
  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. 
V. K. Guduru, A. Granados del Aguila, S. Wenderich, M. K. Kruize, A.   McCollam, P. C. M. Christianen, U. Zeitler, A. Brinkm...
cond-mat.mtrl-sci