Formation of orbital-selective electron states in LaTiO3/SrTiO3 superlattices

The interface electronic structure of correlated LaTiO3/SrTiO3 superlattices is investigated by means of the charge self-consistent combination of the local density approximation (LDA) to density functional theory with dynamical mean-field theory. Utilizing a pseudopotential technique together with a continuous-time quantum Monte Carlo approach, the resulting complex multiorbital electronic states are addressed in a coherent fashion beyond static mean field. General structural relaxations are taken into account on the LDA level and cooperate with the driving forces from strong electronic correlations. This alliance leads to a Ti(3d(xy)) dominated low-energy quasiparticle peak and a lower Hubbard band in line with photoemission studies. Furthermore correlation effects close to the band-insulating bulk SrTiO3 limit as well as the Mott-insulating bulk LaTiO3 limit are studied via realistic single-layer embeddings.