Dual fermion approach to the two-dimensional Hubbard model: Antiferromagnetic fluctuations and Fermi arcs - Condensed Matter > Strongly Correlated ElectronsReport as inadecuate




Dual fermion approach to the two-dimensional Hubbard model: Antiferromagnetic fluctuations and Fermi arcs - Condensed Matter > Strongly Correlated Electrons - Download this document for free, or read online. Document in PDF available to download.

Abstract: We present an efficient diagrammatic method to describe nonlocal correlationeffects in lattice fermion Hubbard-like models, which is based on a change ofvariables in the Grassmann path integrals. The new fermions are dual to theoriginal ones and correspond to weakly interacting quasiparticles in the caseof strong local correlations in the Hubbard model. The method starts withdynamical mean-field theory as a zeroth-order approximation and includesnon-local effects in a perturbative way. In contrast to cluster approaches,this method utilizes an exact transition to a dual set of variables. Ittherefore becomes possible to treat the irreducible vertices of an effective{\it single-impurity} problem as small parameters. This provides a veryefficient interpolation between band-like weak-coupling and atomic limits. Themethod is illustrated on the two-dimensional Hubbard model. Theantiferromagnetic pseudogap, Fermi-arc formations, and non-Fermi-liquid effectsdue to the van Hove singularity are correctly reproduced by the lowest-orderdiagrams. Extremum properties of the dual fermion approach are discussed interms of the Feynman variational principle.



Author: A. N. Rubtsov, M. I. Katsnelson, A. I. Lichtenstein, A. Georges

Source: https://arxiv.org/







Related documents