NON-FERMI-LIQUID FIXED-POINT

We study an exchange interaction in which conduction electrons with ps eudospin S-c=3/2 interact with the impurity spin S-l=1/2. Due to the o verscreening of the impurity spin by higher conduction electron spin, a nontrivial intermediate-coupling-strength fixed point is realized. U sing the numerical renormalization group (NRG), we show that the low-e nergy spectra are described by a non-Fermi-liquid excitation spectrum. A conformal field theory analysis is compared with NRG results and ex cellent agreement is obtained. Using the double-fusion rule to generat e the operator spectrum with the conformal theory, we find that the sp ecific heat coefficient and magnetic susceptibility will diverge as T- 2/3, that the scaling dimension of an applied magnetic field is 5/6, a nd that exchange anisotropy is always relevant. We discuss the possibl e relevance of our work to two-level-system Kondo materials and dilute cerium alloys, and we point out a paradox in understanding the Bethe- ansatz solutions to the multichannel Kondo model.