The spectral properties of La$_{ 1-x}$Sr$_{ x}$TiO$_{ 3}$, a doped Mott insulator with strong Coulomb correlations, are calculated with the ab initio computational scheme LDA+DMFT(QMC). It starts from the non-interacting electronic band structure as calculated by the local density approximation (LDA), and introduces the missing correlations by the dynamical mean-field theory (DMFT), using numerically exact quantum Monte-Carlo (QMC) techniques to solve the resulting self-consistent multi-band single-impurity problem. The results of the LDA+DMFT(QMC) approach for the photoemission spectra of La$_{ 1-x}$Sr$_{ x}$TiO$_{ 3}$ are in good agreement with experiment and represent a considerable qualitative and quantitative improvement on standard LDA calculations.
Categories: cond-mat.str-el cond-mat.mtrl-sci