Electronic structure of SrVO3(001) surfaces: a local-density approximation plus dynamical mean-field theory calculation

摘要

The influence of local Coulomb correlations on the surface electronic structure of SrVO3, a strongly-correlated metal in a perovskite structure, is investigated for both the SrO-layer and VO2-layer-terminated (001) surfaces. The electronic structure within the local density approximation of a semi-infinite surface is determined using the embedded Green-function approach, and the resultant density of states projected on the V t2g orbitals is used as an input to a subsequent many-body calculation within the dynamical mean field theory (DMFT) and the multiorbital quantum Monte Carlo technique. Qualitatively, the present study confirms the conclusion of recent photoemission experiments and tight-binding DMFT calculations which both indicate that the electronic structure at the surface is more strongly correlated than in the bulk. On a quantitative level significant differences are obtained as a function of orbital polarization at the surface, surface layer relaxation, and SrO vs VO2 surface termination.