title: Spin-selective Kondo insulator: cooperation of ferromagnetism and the Kondo effect.
abstract: We propose the notion of a spin-selective Kondo insulator, which provides a fundamental mechanism to describe the ferromagnetic phase of the Kondo lattice model with antiferromagnetic coupling. This unveils a remarkable feature of the ferromagnetic metallic phase: the majority-spin conduction electrons show metallic while the minority-spin electrons show insulating behavior. The resulting Kondo gap in the minority-spin sector, which is due to the cooperation of ferromagnetism and partial Kondo screening, evidences a dynamically induced commensurability for a combination of minority-spin electrons and parts of localized spins. Furthermore, this mechanism predicts a nontrivial relation between the macroscopic quantities such as electron magnetization, spin polarization, and electron filling.
authors.affiliation: Department of Physics, Kyoto University, Kyoto 606-8502, Japan. peters@scphys.kyoto-u.ac.jp
authors.forename: Robert
authors.initials: R
authors.lastname: Peters
authors.forename: Norio
authors.initials: N
authors.lastname: Kawakami
authors.forename: Thomas
authors.initials: T
authors.lastname: Pruschke