Non-Fermi Liquid Behavior of U-impurity with \mbi{f}2-Singlet Ground State
Abstract
It is shown by the Wilson numerical renormalization-group approach that a U-impurity with an f2-singlet ground state exhibits an unstable non-Fermi liquid (NFL) fixed point due to the balance between Kondo singlet and crystalline-electric-field singlet ground state. The puzzling behavior of R1-xUxRu2Si2 (R=Th, Y and La, x≤ 0.07) can be explained if we assume that the singlet ground state is realized and the Kondo temperatures in each orbital are of different orders of magnitude. For a wide region in parameter space, the system shows the NFL behavior as a transient phenomenon in a experimentally possible temperature range. Results for the temperature dependence of resistivity, magnetic susceptibility and the Sommerfeld coefficient with and without a magnetic field reproduce the behavior observed in Th1-xUxRu2Si2. Less anomalous properties of R1-xUxRu2Si2 (R=Y and La) can be understood in the same scenario provided that these compounds have different sets of parameters.
- Publication:
-
Journal of the Physical Society of Japan
- Pub Date:
- February 2002
- DOI:
- 10.1143/JPSJ.71.389
- arXiv:
- arXiv:cond-mat/0109072
- Bibcode:
- 2002JPSJ...71..389Y
- Keywords:
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- Condensed Matter - Strongly Correlated Electrons
- E-Print:
- 4pages, 6figures