Dual Fermion Dynamical Cluster Approach for Strongly Correlated Systems
Abstract
We have designed a new multi-scale approach for Strongly Correlated Systems by combining the Dynamical Cluster Approximation (DCA) and the recently introduced dual-fermion formalism. This approach employs an exact mapping from a real lattice to a DCA cluster of linear size Lc embedded in a dual fermion lattice. Short-length-scale physics is addressed by the DCA cluster calculation, while longer-length-scale physics is addressed diagrammatically using dual fermions. The bare and dressed dual Fermionic Green functions scale as O(1/Lc) so perturbation theory on the dual lattice converges very quickly. E.g., the dual Fermion self-energy calculated with simple second order perturbation theory is of order O(1/Lc^3), with third order and three body corrections down by an additional factor of O(1/Lc^2).
Cite
@article{arxiv.1104.3854,
title = {Dual Fermion Dynamical Cluster Approach for Strongly Correlated Systems},
author = {S. -X. Yang and H. Fotso and H. Hafermann and K. -M. Tam and J. Moreno and T. Pruschke and M. Jarrell},
journal= {arXiv preprint arXiv:1104.3854},
year = {2011}
}