Two-Dimensional Superconducting Phase in LaTiO3/SrTiO3 Heterostructures Induced by High-Mobility Carrier Doping

In this Letter, we show that a superconducting two-dimensional electron gas is formed at the LaTiO₃/SrTiO₃ interface whose transition temperature can be modulated by a back-gate voltage. The gas consists of two types of carriers: a majority of low-mobility carriers always present, and a few high-mobility ones that can be injected by electrostatic doping. The calculation of the electron spatial distribution in the confinement potential shows that the high-mobility electrons responsible for superconductivity set at the edge of the gas whose extension can be tuned by the field effect.