Second-order dual fermion approach to the Mott transition in the two-dimensional Hubbard model
Abstract
We apply the dual fermion approach with a second-order approximation to the self-energy to the Mott transition in the two-dimensional Hubbard model. The approximation captures nonlocal dynamical short-range correlations as well as several features observed in studies using cluster dynamical mean-field theory. This includes a strong reduction of the critical interaction and inversion of the slope of the transition lines with respect to single-site dynamical mean-field theory. We show that these effects coincide with a much smaller momentum differentiation compared to cluster methods. We further discuss the role of the self-consistency condition and show that the approximation behaves as an asymptotic series at low temperature.
Keywords
Cite
@article{arxiv.1805.08572,
title = {Second-order dual fermion approach to the Mott transition in the two-dimensional Hubbard model},
author = {Erik G. C. P. van Loon and Mikhail I. Katsnelson and Hartmut Hafermann},
journal= {arXiv preprint arXiv:1805.08572},
year = {2018}
}
Comments
11 pages, 12 figures