Hubbard model in high dimensions: A perturbation expansion about the atomic limit
✍ Scribed by Walter Metzner
- Publisher
- Elsevier Science
- Year
- 1990
- Tongue
- English
- Weight
- 224 KB
- Volume
- 165-166
- Category
- Article
- ISSN
- 0921-4526
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✦ Synopsis
We discuss a perturbation expansion about the atomic limit of the Hubbard model, i.e. the inter-atomic hopping of electrons is treated as a perturbation. Diagrammatic rules for the calculation of the Green's function of the d-dimensional Hubbard model are described. In the limit of high lattice dimensions only the subclass of fully two-particle reducible diagrams contributes. In this case a proper renormalization of the perturbation expansion reduces the solution of the Hubbard model to a zero-dimensional problem. The renormalized expansion yields approximate solutions which interpolate between the atomic and the free fermion limit.