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arXiv · 1805.10996

Impact of self-consistency in dual fermion calculations

Tin Ribic·Patrik Gunacker·Karsten Held
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Abstract

The dual fermion (DF) method allows for calculating corrections due to non-local correlations relative to an effective impurity model. Choosing the impurity as that of a dynamical mean field theory (DMFT) solution at self-consistency is popular, and the corrections from dual fermion theory are physically meaningful. We investigate the effect of choosing the impurity instead in a self-consistent manner and find for the two dimensional Hubbard model an exponentially increase of the correlation length and susceptibility at low temperatures. There are pronounced differences for the two self-consistency schemes that are discussed in the literature; the self-consistent DF solution can even be more metallic than the DMFT solution.

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Tin Ribic, Patrik Gunacker, Karsten Held. 2018-05-28. Impact of self-consistency in dual fermion calculations. https://doi.org/10.1103/physrevb.98.125106

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