A complete Bethe ansatz solution of the (Formula presented) 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 (Formula presented) we find a Fermi-liquid fixed point, with the impurity spin completely screened. For (Formula presented) the impurity is overscreened and the model has NFL properties. The form the NFL behavior takes depends on the (Formula presented) and (Formula presented) for (Formula presented) the specific heat and the susceptibility are dominated by the NFL contributions; for (Formula presented) the leading contributions are Fermi-liquid-like, and the NFL behavior can be seen only to subleading order; and for (Formula presented) the behavior is marginal. We also analyze the possibility of physical realizations. We show by a detailed renormalization-group and (Formula presented) analysis that the tunneling (Formula presented)-state problem can be mapped into the (Formula presented) 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 (Formula presented) model if the parameters of the dots are tuned appropriately.
|Original language||English (US)|
|Number of pages||28|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|State||Published - 1998|
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics