Lattice relaxation in oxide heterostructures: LaTiO3/SrTiO3 superlattices.
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.
Okamoto
Satoshi
S
Department of Physics, Columbia University, 538 West 120th Street, New York, NY 10027, USA. okapon@phys.columbia.edu
Millis
Andrew J
AJ
Spaldin
Nicola A
NA