Determine the spatial locality of self-energy of LiFeAs

Understanding of the electronic correlations is crucial to explain the electronic properties, magnetism, and superconductivity of the iron-based superconductors (FeSCs). An important question is the degree of spatial locality of the electronic correlations. Local correlations is the starting point of dynamical mean-field theory (DMFT), which has been proved to be powerful in understanding spectroscopic properties of the FeSCs [1,2]. However, recent theoretical and experimental reports on one of the FeSCs, LiFeAs, suggested the importance of non local correlations[3,4]. In this presentation, we extract spatially resolved and orbital dependent electronic self-energy of LiFeAs from angle resolved photoemission spectroscopy with density functional theory as a reference frame, and discuss the level of locality in the different orbitals, with the xy orbital being more local than the xz yz. We also discuss how the level of non locality depends on energy.

[1] H. Miao et al., PRB 98, 020502 (2018)
[2] H. Miao et al., PRB 94, 201109 (2016)
[3] K. Zantout et al., ArXiv:1906:11853v1 (2019)
[4] J. Fink et al., PRB 99, 245156 (2019)