Correlation effect on effective model with realistic electronic structure for heavy fermion compound YbAl3

Abstract

Based on the recently proposed effective Hamiltonian for typical heavy fermion compound YbAl3, the correlation effect is systematically investigated in the physical properties. The band part of the Hamiltonian consists of conduction bands described by nearly free electron method, hybridization between the conduction and 4f-electrons, and the localized 4f-states of Yb ions on the lattice site. The correlation effect is considered by using the self-consistent perturbation theory with local approximation. The temperature dependence of the specific heat coefficient is calculated, and the anomalous behaviors are found in the low temperature region in accord with the experiments. We show that the anomalies may originate from the correlation effect and the structure of the non-interacting density of states.