Evaluation of Fermi surfaces, single and two-particle spectral properties for FeSe using Quasi-particle self consistent GW + DMFT

Most of the first principles techniques, based on DFT or DFT+DMFT frameworks, fails to reproduce the spectral properties of the FeSe both in the tetragonal and orthorhombic phases. Within our recently developed quasi-particle self-consistent GW coupled to DMFT, we show how proper estimations of the non-local fluctuations and local spin fluctuations reproduce the spectral properties in very good agreement with the experiments. We also compute the spin-wave excitation spectra and find momentum dependent shifts in spin-fluctuation weights across the structural transition at 90 K. We rigorously show how these compare with the extant experimental findings.