GHz operation of LaAlO$_{3}$/ SrTiO$_{3}$-based transistor*

Local modification of the metal-insulator transition of the LaAlO$_{3}$ /SrTiO$_{3}$ interface with a conducting-atomic force microscope (c-AFM) has resulted in a variety of electrical\footnote{C. Cen, S. Thiel, J. Mannhart, and J. Levy, Science \textbf{323}, 1026 (2009).} and photonic\footnote{P. Irvin, Y. Ma, D. F. Bogorin, C. Cen, C. W. Bark, C. M. Folkman, C.-B. Eom, and J. Levy, Nature Photonics advanced online publication, 14 Nov.2010 (DOI 10.1038/nphoton.2010.238)} devices. Using a heterodyne measurement technique, we show that a sketch-based, nanoscale transistor (``SketchFET'') can operate at frequencies in excess of 1 GHz. This demonstration of GHz functionality opens the door for new applications for oxide-based, rewritable nanoscale devices.