Calculation of photoemission spectra of the doped Mott insulator La 1 − x Sr x TiO 3 using LDA + DMFT ( QMC )

The spectral properties of La1−xSrxTiO3, 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 La1−xSrxTiO3 are in good agreement with experiment and represent a considerable qualitative and quantitative improvement on standard LDA calculations. PACS. 71.27.+a Strongly correlated electron systems; heavy fermions – 74.25.Jb Electronic structure – 79.60.-i Photoemission and photoelectron spectra