The electronic reconstruction at the interface between two insulating oxides can give rise to a highly-conductive interface. In analogy to this remarkable interface-induced conductivity we show how, additionally, magnetism can be induced at the interface between the otherwise nonmagnetic insulating perovskites SrTiO3 and LaAlO3. A large negative magnetoresistance of the interface is found, together with a logarithmic temperature dependence of the sheet resistance. At low temperatures, the sheet resistance reveals magnetic hysteresis. Magnetic ordering is a key issue in solid-state science and its underlying mechanisms are still the subject of intense research. In particular, the interplay between localized magnetic moments and the spin of itinerant conduction electrons in a solid gives rise to intriguing many-body effects such as Ruderman-Kittel-Kasuya-Yosida (RKKY) interactions, the Kondo effect, and carrier-induced ferromagnetism in diluted magnetic semiconductors. The conducting oxide interface now provides a versatile system to induce and manipulate magnetic moments in otherwise nonmagnetic materials.
@article{arxiv.cond-mat/0703028,
title = {Magnetic effects at the interface between nonmagnetic oxides},
author = {A. Brinkman and M. Huijben and M. van Zalk and J. Huijben and U. Zeitler and J. C. Maan and W. G. van der Wiel and G. Rijnders and D. H. A. Blank and H. Hilgenkamp},
journal= {arXiv preprint arXiv:cond-mat/0703028},
year = {2007}
}