Quantum Monte-Carlo simulation of FeAs-based superconductors

The generalized quantum Monte Carlo algorithm is developed and used to calculate the energy,occupation numbers,and correlations functions of finite FeAs clusters in the two-orbital model at finite temperatures.The coding of quantum states made it possible to take into account complex exchange terms between the orbitals.The results for the calculation of the thermodynamic characteristics of finite two-dimensional FeAs clusters simulating iron-based superconductors have been obtained.The calculated correlation functions indicate the possibility of the effective attraction of charge carriers.