Abstract
A complete Bethe ansatz solution of the Coqblin-Schrieffer model and a detailed analysis of some physical applications of the model are given. As in the usual multichannel Kondo model, a variety of Fermi-liquid and non-Fermi-liquid (NFL) fixed points is found, whose nature depends on the impurity representation μ. For we find a Fermi-liquid fixed point, with the impurity spin completely screened. For the impurity is overscreened and the model has NFL properties. The form the NFL behavior takes depends on the and for the specific heat and the susceptibility are dominated by the NFL contributions; for the leading contributions are Fermi-liquid-like, and the NFL behavior can be seen only to subleading order; and for the behavior is marginal. We also analyze the possibility of physical realizations. We show by a detailed renormalization-group and analysis that the tunneling -state problem can be mapped into the exchange model, and discuss the subtle differences between the two models. As another physical realization we suggest a double quantum dot structure that can be described by means of an model if the parameters of the dots are tuned appropriately.
- Received 27 February 1998
DOI:https://doi.org/10.1103/PhysRevB.58.3814
©1998 American Physical Society