Heterointerfaces*

The interface between a Mott insulator, RTiO₃ (where R is a rare-earth element), and SrTiO₃ hosts an ultra-high density two-dimension electron gas, which can display a broad range of correlated electron phenomena, ranging from magnetism to superconductivity. Due to the dielectric constant of SrTiO₃, up to ~30,000 at low temperatures, the use of SrTiO₃ as a top-gate dielectric is expected to provide new opportunities for locally tuning the very large electron densities which are present in complex oxide interface devices. We discuss the fabrication and electrical measurements of top-gated Hall bars based on hybrid MBE-grown NdTiO₃/SrTiO₃ heterostructures.