Formation of localized magnetic states in a large-spin Fermi system

Abstract

We extend the Anderson impurity model to a large-spin Fermi system with spin $f$=3/2, stimulated by the realization of large-spin ultracold Fermi atoms. The condition required for the spontaneous formation of local magnetic moments is examined and the ground state mean-field magnetic phase diagram is explored carefully. We find that the spin-3/2 Fermi system involves magnetic phase regions I, II, and III that correspond to one, two, and three particle/hole occupation, respectively. In addition, it is observed that all the three magnetic phases have four-fold degenerate ground states. Finally, the phase transition between the three phases seems to be of the first-order.