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 (less than or similar to 2 nm) interface-adjacent SrTiO3 region for n(s) lower than a threshold value n(c) similar to 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.

Spontaneous 2-Dimensional Carrier Confinement at the n-Type SrTiO3/LaAlO3 Interface / Delugas, Pietro Davide; Filippetti, A; Fiorentini, V; Bilc, Di; Fontaine, D; Ghosez, P.. - In: PHYSICAL REVIEW LETTERS. - ISSN 0031-9007. - 106:16(2011), pp. 1-4. [10.1103/PhysRevLett.106.166807]

Spontaneous 2-Dimensional Carrier Confinement at the n-Type SrTiO3/LaAlO3 Interface

DELUGAS, Pietro Davide;
2011-01-01

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 (less than or similar to 2 nm) interface-adjacent SrTiO3 region for n(s) lower than a threshold value n(c) similar to 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.
2011
106
16
1
4
166807
http://doi.org/10.1103/PhysRevLett.106.166807
Delugas, Pietro Davide; Filippetti, A; Fiorentini, V; Bilc, Di; Fontaine, D; Ghosez, P.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/20.500.11767/32500
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