Nonlocal correlation effects in fermionic many-body systems: Overcoming the noncausality problem

Motivated by the intriguing physics of quasi-two-dimensional fermionic systems, such as high-temperature superconducting oxides, layered transition metal chalcogenides, or surface interface development many-body computational methods geared at including both local and nonlocal electronic correlations has become a rapidly evolving field. It been realized, however, that success can be hampered emergence noncausal features in effective observable quantities involved. Here, we present an approach wherein techniques dynamical mean-field theory (DMFT) are extended to interactions, which preserves causality physically intuitive interpretation. Our strategy implications for general class DMFT-inspired adapted cluster, dual boson, fermion with minimal effort.