Dynamical cluster approximation within an augmented plane wave framework: Spectral properties of SrVO ₃

We present a combination of local-density approximation (LDA) with the dynamical cluster approximation (LDA+DCA) in the framework of the full-potential linear augmented plane wave method, and compare our LDA+DCA results for SrVO ₃ to LDA with the dynamical mean-field theory (LDA+DMFT) calculations as well as experimental observations on SrVO ₃. We find a qualitative agreement of the momentum resolved spectral function with angle-resolved photoemission spectra (ARPES) and former LDA+DMFT results. As a correction to LDA+DMFT, we observe more pronounced coherent peaks below the Fermi level, as indicated by ARPES experiments. In addition, we resolve the spectral functions in the K ₀=(0,0,0) and K ₁=(π,π, π) sectors of DCA, where band insulating and metallic phases coexist. Our approach can be applied to correlated compounds where not only local quantum fluctuations but also spatial fluctuations are important.