Controlling interfacial states in amorphous/crystalline LaAlO_3/SrTiO_3 heterostructures by electric fields

摘要

The tunable metal-insulator transition in crystalline LaAlO_3/SrTiO_3 heterostructures constitutes a central element in the range of remarkable interface properties that has made this oxide system subject to extensive research. Recently, metallic interfaces have also been realized when depositing amorphous LaAlO3 films on SrTiO_3. Here, we present a non-volatile and reversible tuning of the interface conductivity by more than 3 orders of magnitude at room temperature by applying an electric field to such amorphous/crystalline heterostructures with amorphous LaAlO_3 film thicknesses of ～2nm. We show that the tunability is strongly temperature dependent, and demonstrate a simple protocol for enhancing the tunability.