  The conducting quasi-two dimensional electron system (q2DES) formed at the
interface between LaAlO3 and SrTiO3 band insulators is confronting the
condensed matter physics community with new paradigms. While the mechanism for
the formation of the q2DES is debated, new conducting interfaces have been
discovered paving the way to possible applications in electronics, spintronics
and optoelectronics. This chapter is an overview of the research on the LAO/STO
sys-tem, presenting some of the most important results obtained in the last
decade to clarify the mechanism of formation of the q2DES at the oxide
interfaces and its peculiar electronic properties as compared to semiconducting
2D-electron gas.
