Okamoto S, Millis AJ, Spaldin NA. Lattice relaxation in oxide heterostructures: LaTiO3/SrTiO3 superlattices.
PHYSICAL REVIEW LETTERS 2006;
97:056802. [PMID:
17026128 DOI:
10.1103/physrevlett.97.056802]
[Citation(s) in RCA: 75] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2006] [Indexed: 05/12/2023]
Abstract
Local density approximation + Hubbard U and many-body effective Hamiltonian calculations are used to determine the effects of lattice relaxation in LaTiO3/SrTiO3 superlattices. Large ferroelectric-like distortions of the TiO6 octahedra are found, which substantially affect the Ti d-electron density, bringing the calculated results into good agreement with experimental data. The relaxations also change the many-body physics, leading to a novel symmetry-breaking-induced ordering of the xy orbitals, which does not occur in bulk LaTiO3, or in the hypothetical unrelaxed structure.
Collapse