Transistor operation and mobility enhancement in top-gated LaAlO3/SrTiO3 heterostructures

We report the operation of LaAlO3/SrTiO3 depletion mode top-gated junction field-effect transistors using a range of LaAlO3 thicknesses as the top gate insulator. Gated Hall bars show near ideal transistor characteristics at room temperature with on-off ratios greater than 1000. Lower temperature measurements demonstrate a systematic increase in the Hall mobility as the sheet carrier density in the channel is depleted via the top gate, providing a route to higher mobility, lower density electron gases in this system.