Analysis of the nature of the peak structure of Hubbard subbands using the quantum Monte Carlo method

It has been shown that the description of the details of the electronic spectra obtained by the combination of the dynamical mean field theory, quantum Monte Carlo methods, and the maximum entropy method can be significantly improved by changing the last method to optimal regularization of the analytic continuation of the Green's function to the real frequency axis. Starting with the quantum Monte Carlo data, this method has reconstructed peaks in the structure of Hubbard subbands with a maximum error of $0.001$ to $0.01$. Owing to the universality of the quantum Monte Carlo method, by varying hybridization, it is possible to determine the features of the hybridized function that are responsible for the formation of the structure of Hubbard subbands. It has been shown that there is no direct relation between the peak structure of subbands and the central Kondo peak. The result indicates the charge nature of resonances responsible for the formation of the peak structure.