Metal-insulator-transition in SrTiO3 induced by argon bombardment combined with field effect

Abstract

By fabricating the Field-Effect-Transistors on argon bombardment SrTiO3 substrates, not only we have achieved one of the best mobility for Field-Effect-Transistors fabricated on SrTiO3, but also realized strong field induced Metal-Insulator-Transition. The critical sheet resistance for the Metal-Insulator-Transition is only 1/7 of the value obtained in the former experiments, indicating a different mechanism. Further study shows that the Metal-Insulator-Transition can be attributed to the oxygen vacancies formed after the bombardment becoming the electron donor under the electric field modulation, increasing SrTiO3 surface electron density and transforming the substrate into metallic state.