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arXiv · 1104.3854

Dual Fermion Dynamical Cluster Approach for Strongly Correlated Systems

S. -X. Yang·H. Fotso·H. Hafermann·K. -M. Tam·J. Moreno·T. Pruschke·M. Jarrell
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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).

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S. -X. Yang, H. Fotso, H. Hafermann, K. -M. Tam, J. Moreno, T. Pruschke, M. Jarrell. 2011-04-19. Dual Fermion Dynamical Cluster Approach for Strongly Correlated Systems. https://doi.org/10.1103/physrevb.84.155106

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