Spectral Properties of Correlated Materials: Local Vertex and Nonlocal Two-Particle Correlations from Combined GW and Dynamical Mean Field Theory
Ayral, ThomasTheoretical Physics, ETH Zurich, Switzerland - Centre de Physique Théorique, Ecole Polytechnique, Palaiseau, France - Institut de Physique Théorique, Gif-sur-Yvette, France
Werner, PhilippDepartment of Physics, University of Fribourg, Switzerland - Theoretical Physics, ETH Zurich, Switzerland
Biermann, SilkeCentre de Physique Théorique, Ecole Polytechnique, Palaiseau, France - Japan Science and Technology Agency, CREST, Kawaguchi, Japan
English
We present a fully self-consistent combined GW and dynamical mean field (DMFT) study of the extended two-dimensional Hubbard model. The inclusion of the local dynamical vertex stemming from the DMFT self-energy and polarization is shown to cure the known problems of self-consistent GW. We calculate momentum-resolved spectral functions, two-particle polarizations, and electron-loss spectra, as well as the effective dynamical interaction induced by nonlocal screening. The momentum-dependence introduced by GW into the extended DMFT description leads to a narrowing of the quasiparticle width and more pronounced Hubbard bands in the metallic regime as one approaches the charge-ordering transition. It further affects the shape of collective modes, giving rise to dispersive plasmon-like long-wavelength and stripe modes.