Insulator-to-metal phase transition in Yb-based Kondo insulators
Department of Physics, Tsinghua University - Beijing 100084, China
2 Institute of Physics, Chinese Academy of Sciences - Beijing 100190, China
3 Institute of Theoretical Physics, Chinese Academy of Sciences - Beijing 100190, China
Accepted: 20 August 2010
The periodic Anderson lattice model for the crystalline electric field (CEF) split 4f quartet states is used to describe the Yb-based Kondo insulators. In the slave-boson mean-field approximation, we derive the hybridized quasiparticle bands, and surprisingly find that decreasing the hybridization difference of the two CEF quartets may induce a continuous insulator-to-metal phase transition. The resulting metallic phase has a hole and an electron Fermi pocket. Such a phase transition may be realized experimentally by applying pressure, reducing the difference in hybridization of the two CEF quartets in real materials.
PACS: 75.30.Mb – Valence fluctuation, Kondo lattice, and heavy-fermion phenomena / 71.27.+a – Strongly correlated electron systems; heavy fermions / 75.20.Hr – Local moment in compounds and alloys; Kondo effect, valence fluctuations, heavy fermions
© EPLA, 2010