Lattice polarization effects on electron-gas charge densities in ionic superlattices

Abstract

The atomic-level control achievable in artificially-structured oxide superlattices provides a unique opportunity to explore interface phases of matter including high-density 2D electron gases. Electronic-structure calculations show that the charge distribution of the 2D gas is strongly modulated by electron-phonon interactions with significant ionic polarization. Anharmonic finite-temperature effects must be included to reproduce experiment. Density functional perturbation theory is used to parameterize a simple model introduced to represent these effects and predict temperature dependencies.

16 pages including figures Added references 5 and 24, structure picture to Fig. 4, and new paragraph at end of Sec. III

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