2017/01/31 by Thomas Ayral, Silke Biermann, Philipp Werner +1 · 2 citations
Mathematics · Physics and Astronomy · #Advanced Condensed Matter Physics #Boson #Coulomb #Electron #Fock space #Mathematics #Mean field theory #Perturbation (astronomy) #Perturbation theory (quantum mechanics) #Phase (matter) #Phase diagram #Physics #Physics of Superconductivity and Magnetism #Quantum and electron transport phenomena #Quantum electrodynamics #Quantum mechanics #Statistical physics #Vertex (graph theory) #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.95.245130
published as Phys. Rev. B 95, 245130 (2017) · 11 pages, 10 figures
arxiv created 2017/05/05 · openalex publication_date 2017/06/23 · arxiv updated 2017/08/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
In electronic systems with long-range Coulomb interaction, the nonlocal Fock-exchange term has a band-widening effect. While this effect is included in combined many-body perturbation theory and dynamical mean field theory (DMFT) schemes, it is not taken into account in standard extended DMFT (EDMFT) calculations. Here, we include this instantaneous term in both approaches and investigate its effect on the phase diagram and dynamically screened interaction. We show that the largest deviations between previously presented EDMFT and GW+EDMFT results originate from the nonlocal Fock term, and that the quantitative differences are especially large in the strong-coupling limit. Furthermore, we show that the charge-ordering phase diagram obtained in GW+EDMFT methods for moderate interaction values is very similar to the one predicted by dual-boson methods that include the fermion-boson or four-point vertex.