Two-Dimensional Quantum Oscillations of the Conductance at LaAlO 3 / SrTiO 3 Interfaces
Résumé
We report on a study of magnetotransport in LaAlO 3 =SrTiO 3 interfaces characterized by mobilities of the order of several thousands cm 2 =V s. We observe Shubnikov-de Haas oscillations whose period depends only on the perpendicular component of the magnetic field. This observation directly indicates the formation of a two-dimensional electron gas originating from quantum confinement at the interface. From the temperature dependence of the oscillation amplitude we extract an effective carrier mass m à ' 1:45m e. An electric field applied in the back-gate geometry increases the mobility, the carrier density, and the oscillation frequency.