(Invited) Oxide Interface Is the Device: Properties of Two-Dimensional Electron Gas

Transition metal oxides exhibit rich phase diagrams and exotic physical properties as a result of strong correlations between charge, spin, orbital and lattice. The recent advances of thin film technology allow the synthesis of high-quality epitaxial oxide heterostructures with control at the unit cell level, which enables exploring rich physics and opportunities for future technologies. As a notable example, interesting transport phenomena like 2D electron conduction and orbital reconstruction were discovered at the polar-nonpolar LaAlO₃/SrTiO₃ (LAO/STO) interface. In this talk, I will first discuss our results of Kondo effect and two-dimensional insulator-to-metal transition obtained on interface-based field effect device with double layer ionic electrolyte as the top gate. Then I will introduce an interface-based nonvolatile resistive switching device, where the ionic drift and alteration of electronic configuration underpin the memory operation. Finally, I will discuss the possible routes to achieving higher electron mobility in such oxide interfaces and the perspective of constructing interface-based photodetectors.