Continuous-Time Quantum Monte Carlo (CT-QMC) method combined with Dynamical Mean Field Theory (DMFT) is used to calculate both Periodic Anderson Model (PAM) and Kondo Lattice Model (KLM). Different parameter sets of both models are connected by the S
chrieffer-Wolff transformation. For degeneracy N=2, a special particle-hole symmetric case of PAM at half filling which always fixes one electron per impurity site is compared with the results of the KLM. We find a good mapping between PAM and KLM in the limit of large on-site Hubbard interaction U for different properties like self-energy, quasiparticle residue and susceptibility. This allows us to extract quasiparticle mass renormalizations for the f electrons directly from KLM. The method is further applied to higher degenerate case and to realsitic heavy fermion system CeRhIn5 in which the estimate of the Sommerfeld coefficient is proven to be close to the experimental value.
To clarify the role of the Kondo effect in screening local magnetic moments of Plutonium 5f--electrons as well as its competition to the RKKY interactions we use a combination of density functional theory with static Hartree Fock and dynamic Hubbard
1 approximations to calculate the strength of both the Kondo exchange, J_K, and of the RKKY exchange, J_RKKY, couplings for Pu{1-x}Am{x} system as a function of x. We find that J_K increases despite the atomic volume gets larger with the Am doping due to unexpected enhancement of hybridization between f and conduction electrons in the vicinity of the Fermi level. At the same time, the RKKY exchange is shown to reduce smoothly with increasing x. Our results imply that the Kondo effect should be robust against the increase in interatomic spacing of this alloy.
