Theory for Magnetic Anisotropy of Field-Induced Insulator-to-Metal Transition in Cubic Kondo Insulator YbB_{12}

Abstract

Magnetization and energy gap of Kondo insulator YbB_{12} are calculated theoretically based on the previously proposed tight-binding model composed of Yb 5d$\epsilon$ and 4f ${\Gamma }_8$ orbitals. It is found that magnetization curves are almost isotropic, naturally expected from the cubic symmetry, but that the gap-closing field has an anisotropy: the gap closes faster for the field in (100) direction than in (110) and (111) directions, in accord with the experiments. This is qualitatively understood by considering the maximal eigenvalues of the total angular momentum operators projected on each direction of the magnetic field. But the numerical calculation based on the band model yields better agreement with the experiment.

arXiv comment4 pages, 4 figures, to appear in J. Phys. Soc. Jpn

References in corpus (7)

• Optical conductivity of the Kondo insulator YbB_12: Gap formation and low-energy excitations
• Evidence for short-range antiferromagnetic fluctuations in Kondo-insulating YbB12
• Formation Mechanism of Hybridization Gap in Kondo Insulators based on a Realistic Band Model and Application to YbB${}_{12}$
• Insulator-to-metal transition in Kondo insulators under strong magnetic field
• Indirect and direct energy gaps in the Kondo semiconductor YbB12
• Calculation of Optical Conductivity of YbB${}_{12}$ using Realistic Tight-Binding Model
• Self-consistent perturbational study of insulator-to-metal transition in Kondo insulators due to strong magnetic field

Cited by in corpus (3)

• Mean Field study of the heavy fermion metamagnetic transition
• Absence of Hybridization Gap in Heavy Electron Systems and Analysis of YbAl3 in terms of Nearly Free Electron Conduction Band
• Insulator-to-metal phase transition in Yb-based Kondo insulators