Investigation of the two-particle-self-consistent theory for the single-impurity Anderson model and an extension to the case of strong correlation
- Authors
- Publication Date
- Jan 01, 2000
- Source
- Saitama University Cyber Repository of Academic Resources
- Keywords
- License
- Unknown
- External links
Abstract
The two-particle-self-consistent theory is applied to the single-impurity Anderson model. It is found that it cannot reproduce the small energy scale in the strong correlation limit. A modified scheme to overcome this difficulty is proposed by introducing an appropriate vertex correction explicitly. Using the same vertex correction, the self-energy is investigated, and it is found that under certain assumptions it reproduces the result of the modified perturbation theory which interpolates the weak and the strong correlation limits.