True Meaning of “Localized” f-Electrons Measured by dHvA Experiments in Ce-Based Heavy Fermion Metals

Abstract

The true meaning of the terms “localized” and “itinerant”, frequently used in the interpretations of de Haas–van Alphen (dHvA) experiments of Ce-based heavy fermion metals, is argued. If the magnetic field H used in a dHvA measurement is larger than the threshold value of the order of the hybridization gap, the majority band of the quasiparticles would be filled up, and the Fermi surface (FS) would shift to the surface on which the conduction electrons have the Fermi energy without H . Then, the total number of electrons wrapped by the FS appears to decrease by one (f) electron per unit cell of the lattice. This phenomenon has been regarded as the “localization” of f-electrons, although f-electrons are never localized. As explicit examples, the transformation of the FS in CeRhIn 5 and CeIn 3 under pressure and that in CeRu 2 Si 2 near a pseudo-metamagnetic transition are discussed.