Dual Bethe-Salpeter equation for the multiorbital lattice susceptibility within dynamical mean-field theory
(2024) In Physical Review B 109(15).- Abstract
Dynamical mean-field theory describes the impact of strong local correlation effects in many-electron systems. While the single-particle spectral function is directly obtained within the formalism, two-particle susceptibilities can also be obtained by solving the Bethe-Salpeter equation. The solution requires handling infinite matrices in Matsubara frequency space. This is commonly treated using a finite frequency cutoff, resulting in slow linear convergence. A decomposition of the two-particle response in local and nonlocal contributions enables a reformulation of the Bethe-Salpeter equation inspired by the dual boson formalism. The reformulation has a drastically improved cubic convergence with respect to the frequency cutoff,... (More)
Dynamical mean-field theory describes the impact of strong local correlation effects in many-electron systems. While the single-particle spectral function is directly obtained within the formalism, two-particle susceptibilities can also be obtained by solving the Bethe-Salpeter equation. The solution requires handling infinite matrices in Matsubara frequency space. This is commonly treated using a finite frequency cutoff, resulting in slow linear convergence. A decomposition of the two-particle response in local and nonlocal contributions enables a reformulation of the Bethe-Salpeter equation inspired by the dual boson formalism. The reformulation has a drastically improved cubic convergence with respect to the frequency cutoff, considerably facilitating the calculation of susceptibilities in multi-orbital systems. This improved convergence arises from the fact that local contributions can be measured in the impurity solver. The dual Bethe-Salpeter equation uses the fully reducible vertex which is free from vertex divergences. We benchmark the approach on several systems including the spin susceptibility of strontium ruthenate Sr2RuO4, a strongly correlated Hund's metal with three active orbitals.
(Less)
- author
- Van Loon, Erik G.C.P. LU and Strand, Hugo U.R.
- organization
- publishing date
- 2024-04
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Physical Review B
- volume
- 109
- issue
- 15
- article number
- 155157
- publisher
- American Physical Society
- external identifiers
-
- scopus:85191367495
- ISSN
- 2469-9950
- DOI
- 10.1103/PhysRevB.109.155157
- language
- English
- LU publication?
- yes
- id
- 1fc420aa-9745-4ea1-84bb-9836789f445f
- date added to LUP
- 2024-05-03 13:11:09
- date last changed
- 2024-05-03 13:12:13
@article{1fc420aa-9745-4ea1-84bb-9836789f445f,
abstract = {{<p>Dynamical mean-field theory describes the impact of strong local correlation effects in many-electron systems. While the single-particle spectral function is directly obtained within the formalism, two-particle susceptibilities can also be obtained by solving the Bethe-Salpeter equation. The solution requires handling infinite matrices in Matsubara frequency space. This is commonly treated using a finite frequency cutoff, resulting in slow linear convergence. A decomposition of the two-particle response in local and nonlocal contributions enables a reformulation of the Bethe-Salpeter equation inspired by the dual boson formalism. The reformulation has a drastically improved cubic convergence with respect to the frequency cutoff, considerably facilitating the calculation of susceptibilities in multi-orbital systems. This improved convergence arises from the fact that local contributions can be measured in the impurity solver. The dual Bethe-Salpeter equation uses the fully reducible vertex which is free from vertex divergences. We benchmark the approach on several systems including the spin susceptibility of strontium ruthenate Sr2RuO4, a strongly correlated Hund's metal with three active orbitals.</p>}},
author = {{Van Loon, Erik G.C.P. and Strand, Hugo U.R.}},
issn = {{2469-9950}},
language = {{eng}},
number = {{15}},
publisher = {{American Physical Society}},
series = {{Physical Review B}},
title = {{Dual Bethe-Salpeter equation for the multiorbital lattice susceptibility within dynamical mean-field theory}},
url = {{http://dx.doi.org/10.1103/PhysRevB.109.155157}},
doi = {{10.1103/PhysRevB.109.155157}},
volume = {{109}},
year = {{2024}},
}