Gutzwiller theory for the ferromagnetism in the periodic Anderson model

周期アンダーソンモデルの強磁性に対するグッツヴィラー近似法

久保 勝規 

Kubo, Katsunori

In heavy-fermion systems, external pressure and a magnetic field can change the electronic state drastically, such as metamagnetic transition, since the energy scale is very low. To investigate such phenomena, we study the periodic Anderson model by applying the Gutzwiller approximation for states with finite magnetic polarization. Then, 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. We evaluate the magnetization and effective mass and discuss the electronic states in these ferromagnetic states.