Dual fermion approach to the two-dimensional Hubbard model: Antiferromagnetic fluctuations and Fermi arcs
arXiv:0810.3819 · doi:10.1103/PhysRevB.79.045133
Abstract
We present an efficient diagrammatic method to describe nonlocal correlation effects in lattice fermion Hubbard-like models, which is based on a change of variables in the Grassmann path integrals. The new fermions are dual to the original ones and correspond to weakly interacting quasiparticles in the case of strong local correlations in the Hubbard model. The method starts with dynamical mean-field theory as a zeroth-order approximation and includes non-local effects in a perturbative way. In contrast to cluster approaches, this method utilizes an exact transition to a dual set of variables. It therefore becomes possible to treat the irreducible vertices of an effective {\it single-impurity} problem as small parameters. This provides a very efficient interpolation between band-like weak-coupling and atomic limits. The method is illustrated on the two-dimensional Hubbard model. The antiferromagnetic pseudogap, Fermi-arc formations, and non-Fermi-liquid effects due to the van Hove singularity are correctly reproduced by the lowest-order diagrams. Extremum properties of the dual fermion approach are discussed in terms of the Feynman variational principle.
15 pages, 15 figures Second version + minor changes
References in corpus (7)
- Dynamical vertex approximation - a step beyond dynamical mean field theory
- Strongly Correlated Superconductivity: a plaquette Dynamical mean field theory study
- Pseudogap and antiferromagnetic correlations in the Hubbard model
- Influence of Spatial Correlations in Strongly Correlated Electron Systems: Extension to Dynamical Mean Field Approximation
- Dual Fermion Approach to Susceptibility of Correlated Lattice Fermions
- The superconducting gap in the Hubbard model and the two gap energy scales in high-Tc cuprates
- Bond excitations in the pseudogap phase of the Hubbard Model