OXIDE INTERFACES, PERSPECTIVES FOR NEW PHYSICS AND DEVICES
Transistors, lasers and solar cells all involve interfacial phenomena. However, while in semiconductors as one moves-away from the interface “free electron” physics takes place, in oxides strong correlations can play an important role. Spin, orbital, and lattice degrees of freedom in the constituting materials can manifest themselves in a new and interesting way at the interface between oxides, bringing new physical concepts and functionalities.
Since the seminal discovery of Ohtomo and Hwang the interface between SrTiO3 and LaAlO3 became a model system for studying oxide interfaces. Despite the two parent compounds being nonmagnetic insulators a two dimensional electron gas is formed at their interface. This electron gas turned out to be superconducting and magnetic. These properties can be easily tuned using gate voltage that changes the carrier concentration.
In this talk I will review recent developments in oxide interfaces in general and in the LaAlO3/SrTiO3 system in particular. I will describe the physical problems and challenges yet to be surmounted and our group’s effort in this field.