It is shown by the Wilson's numerical renormalization-group approach that Non-Fermi liquid (NFL) behaviors arise even for U-impurity with an f2-singlet ground state, and all the puzzling behaviors of R1−xUxRu2Si2 (R=Th, Y and La, x≤0.07) can be explained on its basis. There exists an unstable NFL fixed point due to the balance between Kondo singlet and Crystalline-Electric-Field singlet ground states. For wide region in parameter space the system shows the NFL behavior as a transient phenomenon in temperature range accessible by experiment. Results for temperature dependence of the resistivity, the magnetic susceptibility and the Sommerfeld coefficient with and without magnetic field reproduce the behaviors observed in Th1−xUxRu2Si2. Less anomalous properties of R1−xUxRu2Si2 (R=Y and La) can be understood along the same scenario provided that those compounds have different sets of parameters.
@article{arxiv.cond-mat/0109072,
title = {Non-Fermi Liquid Behavior of U-impurity with $f^2$-Singlet Ground State},
author = {Satoshi Yotsuhashi and Kazumasa Miyake and Hiroaki Kusunose},
journal= {arXiv preprint arXiv:cond-mat/0109072},
year = {2009}
}