Ferromagnetic states in the periodic Anderson model

周期アンダーソンモデルの強磁性状態

久保 勝規 

Kubo, Katsunori

We study ferromagnetic states in the periodic Anderson model by using the Gutzwiller method. We find three ferromagnetic states: a weakly polarized state, a half-metallic state, and a ferromagnetic state with an almost completely polarized f-electron state. Between these ferromagnetic states, the structure of the Fermi surface is different. In the paramagnetic state, a large Fermi-surface is realized. The topology of the Fermi surface in the weakly polarized state is the same as in the paramagnetic state. In the half-metallic state, the Fermi surface for the majority spin disappears. In the ferromagnetic state with large f-electron polarization, a small Fermi-surface is realized. Then, the phase transitions between these ferromagnetic states accompany change in the Fermi-surface topology, called Lifshitz transitions.