| A growing class of rare-earth and actinide compounds containing localized magnetic moments exhibit anomalous "heavy non-Fermi-liquid" behavior characterized by a T ln T low-temperature variation of the heat capacity and a resistivity which approaches its zero-temperature limit as Tnu where 1 < nu < 2. We propose a mechanism for such non-Fermi-liquid behavior based on "magnetic frustration," a feature of many rare-earth and actinide system. Using numerical renormalization-group methods, we study a Kondo model of three frustrated spin-1/2 impurities coupled to a nonmagnetic conduction band. Two distinct non-Fermi-liquid regimes are found, the first related through an interchange of spin and charge degrees of freedom to the low-temperature limit of the two-channel Kondo model for a single spin-1/2 impurity, while the second regime appears to be completely novel. |
