Theory for Magnetic Anisotropy of Field-Induced Insulator-to-Metal Transition in Cubic Kondo Insulator YbB_{12}
| Autor: | Toshiyuki Izumi, Tetsuro Saso, Yoshiki Imai |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2007 |
| Předmět: |
Physics
Condensed matter physics Strongly Correlated Electrons (cond-mat.str-el) Kondo insulator General Physics and Astronomy FOS: Physical sciences Magnetic anisotropy Magnetization Condensed Matter - Strongly Correlated Electrons Tight binding Kondo effect Metal–insulator transition Anisotropy Electronic band structure |
| Popis: | 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. Comment: 4 pages, 4 figures, to appear in J. Phys. Soc. Jpn |
| Databáze: | OpenAIRE |
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