title: Spontaneous 2-dimensional carrier confinement at the n-type SrTiO3/LaAlO3 interface.
abstract: We describe the intrinsic mechanism of 2-dimensional electron confinement at the n-type SrTiO3/LaAlO3 interface as a function of the sheet carrier density n(s) via advanced first-principles calculations. Electrons localize spontaneously in Ti 3d(xy) levels within a thin (≲2  nm) interface-adjacent SrTiO3 region for n(s) lower than a threshold value n(c)∼10(14)  cm(-2). For n(s)>n(c) a portion of charge flows into Ti 3d(xz)-d(yz) levels extending farther from the interface. This intrinsic confinement can be attributed to the interface-induced symmetry breaking and localized nature of Ti 3d t(2g) states. The sheet carrier density directly controls the binding energy and the spatial extension of the conductive region. A direct, quantitative relation of these quantities with n(s) is provided.
authors: CNR-IOM UOS Cagliari, Dipartimento di Fisica, Università di Cagliari, Monserrato (CA), Italy.
authors: Pietro
authors: P
authors: Delugas
authors: Alessio
authors: A
authors: Filippetti
authors: Vincenzo
authors: V
authors: Fiorentini
authors: Daniel I
authors: DI
authors: Bilc
authors: Denis
authors: D
authors: Fontaine
authors: Philippe
authors: P
authors: Ghosez