The numerical renormalization group method is applied to study a magnetic impurity in a superconductor. The ground state and the first excited state, which are either a doublet (S = 1 2) or a singlet (S = 0), are traced with the renormalization step. The position and the spectral weight of the localized excited state within the energy gap are determined as a function of TK/Δ (TK Kondo temperature, Δ = superconducting energy gap). The present theory gives a reliable description for the whole region of TK/Δ.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering