Itinerant versus localized heavy-electron magnetism.

The nature of the itinerant-localized transition of heavy electrons is clarified for the Kondo-Heisenberg lattice at finite temperatures. The phase diagram and electronic structure are derived by means of the continuous-time quantum Monte Carlo method combined with the dynamical mean-field theory. Around the itinerant-localized transition inside the antiferromagnetic phase, nearly flat bands appear on the Fermi surface with an almost vanishing quasiparticle renormalization factor. At the same time, there emerges a strong local magnetic fluctuation with a minute energy scale. Considering both antiferromagnetic and ferromagnetic Heisenberg interactions, a coherent understanding is achieved on rich phase diagrams observed in CeRh(1-x)Co(x)In5, CeRu2(Si(x)Ge(1-x))2, UGe2, and CeT2Al10 (T=Fe, Ru, Os).