Electrostatic doping of a Mott insulator in an oxide heterostructure: the case of LaVO3/SrTiO3

The discovery of a quasi-two-dimensional electron system at the interface between the two band insulators LaAlO3 and SrTiO3 has triggered intense investigations of oxide heterostructures with other material combinations. The hope is that by combining a polar overlayer with a non-polar substrate electronic reconstruction will lead to highly mobile interface charge carriers with special properties. The formation of a conducting interface layer in epitaxial LaVO3/SrTiO3, where LaVO3 is a Mott insulator, is studied by transport measurements and hard X-ray photoelectron spectroscopy. We identify an insulator-to-metal transition above a critical LaVO3 thickness with transport properties similar to those recently reported for LaAlO3/SrTiO3 interfaces. Interestingly, our photoemission measurements give evidence that electronic charge is transferred exclusively to the LaVO3-side of the interface caused by an electronic reconstruction within the film itself. This opens the opportunity to study a band-filling controlled Mott transition induced by a purely electrostatic mechanism.