Abstract
We present the results of a Wilson renormalization-group study of the single-impurity Kondo and Anderson models in a system with a gap in the conduction-electron spectrum. The behavior of the impurity susceptibility and the zero-frequency response function, are discussed in the cases with and without particle-hole symmetry. For the case of no particle-hole symmetry, we find a transition, as the bandgap increases, from a singlet ground state (when where is the Kondo temperature) to a doublet ground state (when . But there is no such transition for the case with particle-hole symmetry: the ground state is always a doublet. In addition, for the asymmetric Anderson model the correlation functions, , , and are computed.
- Received 26 June 1997
DOI:https://doi.org/10.1103/PhysRevB.57.5225
©1998 American Physical Society