Rewritable nanoscale photodetector at the LaAlO$_{3}$/ SrTiO$_{3}$ interface

It has been demonstrated by Cen. et al that a conducting nanowire can be written or erased at the interface between LaAlO$_{3}$ and SrTiO$_{3}$, using a conducting AFM writing technique.\footnote{C. Cen, S. Thiel, K. E. Andersen, C. S. Hellberg, J. Mannhart, and J. Levy, Nature Materials \textbf{7}, 2136 (2008).}$^,$\footnote{C. Cen, S. Thiel, J. Mannhart, and J. Levy, Science \textbf{323}, 1026 (2009).} We show two-terminal and three-terminal junctions can behave as nanoscale photodetectors. Two-terminal nanowire junctions and three-terminal SketchFETs are excited locally with visible-IR light, and the photoconductive response is measured as a function of position and wavelength. The spatial sensitivity appears to be diffraction-limited, and the photoconductive response extends into the NIR. Both the mechanism and possible applications for this class of devices will be discussed.