Local magnetic moment formation and Kondo screening in the half filled two dimensional single band Hubbard model

Abstract

We study formation of local magnetic moments in strongly correlated Hubbard model within dynamical mean field theory and associate peculiarities of temperature dependence of local charge $\chi_c$ and spin $\chi_s$ susceptibilities with different stages of local moment formation. Local maximum of temperature dependence of the charge susceptibility $\chi_c$ is associated with beginning of local magnetic moments formation, while the minimum of the susceptibility $\chi_c$ and double occupation, as well as low temperature boundary of the plateau of effective local magnetic moment $\mu_{\rm eff}^2=T\chi_s$ temperature dependence are connected with full formation of local moments. We also obtain interaction dependence of the Kondo temperature $T_K$, which is compared to the fingerprint criterion of Phys. Rev. Lett. 126, 056403 (2021). Near the Mott transition the two criteria coincide, while further away from Mott transition the fingerprint criterion somewhat overestimates Kondo temperature. The relation of the observed features to the behavior of eigenvectors/eigenvalues of fermionic frequency-resolved charge susceptibility and divergences of irreducible vertices is discussed.