Dynamical Response and Confinement of the Electrons at the LaAlO 3 / SrTiO 3 Interface
Résumé
With infrared ellipsometry and transport measurements we investigated the electrons at the interface between LaAlO3 and SrTiO3. We obtained a sheet carrier concentration of Ns≈5–9×1013 cm−2, an effective mass of m∗=3.2±0.4me, and a strongly frequency dependent mobility. The latter are similar as in bulk SrTi1−xNbxO3 and therefore suggestive of polaronic correlations. We also determined the vertical concentration profile which has a strongly asymmetric shape with a rapid initial decay over the first 2 nm and a pronounced tail that extends to about 11 nm.