Electronic Structures and f-d Orbital Hybridization of a Heavy Fermion YbNiGa

Abstract

The electromagnetic and thermal properties of a heavy fermion YbNiGa are investigated using first-principle methods with local density approximation (LDA) and LDA+U approaches. The Yb f-bands are located near the Fermi energy and hybridized with the Ni-3d states. This hybridization plays important roles to make characteristics of this material. Band calculation with the LDA framework does not match with that of experimental result because of the strong correlation interaction between f orbitals. The calculation shows that the specific heat coefficient underestimates the experiment value by a factor of 38. The discrepancy is attributed to the formation of quasiparticle. The exchanging interaction between the local f electron and the conduction d electrons will result in the formation of quasiparticle. The exchange interaction between the f and the conduction electrons is large, which makes enhancement the specific heat coefficient.