The interface between lanthanum aluminate (LaAlO 3) and strontium titanate (SrTiO 3) is a notable materials interface because it exhibits properties not found in its constituent materials. Individually, LaAlO 3 and SrTiO 3 are non-magnetic insulators, yet LaAlO 3 /SrTiO 3 interfaces can exhibit electrical metallic conductivity, superconductivity, ferromagnetism, large negative in-plane magnetoresistance, and giant persistent photoconductivity. The study of how these properties emerge at the LaAlO 3 /SrTiO 3 interface is a growing area of research in condensed matter physics.