Correlation Properties and Band Structure of FeAs-based Superconductors

The excitation spectrum is calculated for two-dimensional FeAs clusters modeling iron-based superconductors with the use of the quantum Monte Carlo algorithm in the framework of the full two-orbital model. The data for clusters of the size up to 10×10 FeAs cells are presented for the first time. The dependence of dispersion curves on temperature and interaction parameters is analyzed.