Quantum Monte Carlo Study of the Degenerate Anderson Model with Cubic Crystal Field

Abstract

Using a quantum Monte Carlo simulation technique, we study magnetic properties of the 6-fold degenerate Anderson model, which corresponds to the angular momentum j =5/2. The model is characterized by the f - f Coulomb interaction U , the hybridization width Γ, and the f -electron energy level E f . As U increases, the Kondo temperature T K decreases for the electron-hole symmetric case ( E f ∼-5 U /2), although T K increases for the shallow E f case ( E f ∼0). We also study an effect of cubic crystal field splitting Δ c on the susceptibility and the Kondo temperature, and find a suppression of susceptibility and an increase of T K when the occupied f -electron number is nearly equal to one. In processes of Monte Carlo simulations, the negative sign problem does not appear.