Abstract
We develop a Non-Crossing Approximation (NCA) for the effective cluster problem of the recently developed Dynamical Cluster Approximation (DCA). The DCA technique includes short-ranged correlations by mapping the lattice problem onto a self-consistently embedded periodic cluster of size Nc. It is a fully causal and systematic approximation to the full lattice problem, with corrections script O sign(1/Nc) in two dimensions. The NCA we develop is a systematic approximation with corrections script O sign(1/N3c). The method will be discussed in detail and results for the one-particle properties of the Hubbard model are shown. Near half filling, the spectra display pronounced features including a pseudogap and non-Fermi-liquid behavior due to short-ranged antiferromagnetic correlations.
| Original language | English |
|---|---|
| Pages (from-to) | 613-624 |
| Number of pages | 12 |
| Journal | Zeitschrift für Physik B Condensed Matter |
| Volume | 13 |
| Issue number | 4 |
| DOIs | |
| State | Published - Feb 2 2000 |
| Externally published | Yes |
Keywords
- 71.10.Fd Lattice fermion models (Hubbard model, etc.)
- 71.27.+a Strongly correlated electron systems; heavy fermions
- 75.20.Hr Local moment in compounds and alloys; Kondo effect, valence fluctuations, heavy fermions