Eur. Phys. J. B 18, 55-61 (2000)
https://doi.org/10.1007/s100510070077

Calculation of photoemission spectra of the doped Mott insulator La_1-xSr_xTiO₃ using LDA+DMFT(QMC)

¹ Institute of Metal Physics, Russian Academy of Sciences-Ural Division, 620219 Yekaterinburg GSP-170, Russia
² Theoretische Physik III, Elektronische Korrelationen und Magnetismus, Universität Augsburg, 86135 Augsburg, Germany

Received: 20 May 2000
Revised: 27 July 2000
Published online: 15 November 2000

Abstract

The spectral properties of La_1-xSr_xTiO₃, 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-xSr_xTiO₃ are in good agreement with experiment and represent a considerable qualitative and quantitative improvement on standard LDA calculations.