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Second-order phase transitions and divergent linear response in dynamical mean-field theory

Van Loon, Erik G.C.P. LU orcid (2024) In Physical Review B 109(24).
Abstract

Second-order phase transitions appear as a divergence in one of the linear response functions. For a system of correlated electrons, the relevant divergent response can and does involve many-particle observables, most famously the double occupancy. Generally, evaluating the linear response function of many-particle observables requires a many-particle generalization of the Bethe-Salpeter equation. However, here I show that the divergence of linear response functions in dynamical mean-field theory is governed by a two-particle Bethe-Salpeter equation, even for many-particle observables. The reason for this is that the divergence at the second-order phase transition is produced by the self-consistent feedback of the dynamical mean... (More)

Second-order phase transitions appear as a divergence in one of the linear response functions. For a system of correlated electrons, the relevant divergent response can and does involve many-particle observables, most famously the double occupancy. Generally, evaluating the linear response function of many-particle observables requires a many-particle generalization of the Bethe-Salpeter equation. However, here I show that the divergence of linear response functions in dynamical mean-field theory is governed by a two-particle Bethe-Salpeter equation, even for many-particle observables. The reason for this is that the divergence at the second-order phase transition is produced by the self-consistent feedback of the dynamical mean field.

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Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Physical Review B
volume
109
issue
24
article number
L241110
publisher
American Physical Society
external identifiers
  • scopus:85196271129
ISSN
2469-9950
DOI
10.1103/PhysRevB.109.L241110
language
English
LU publication?
yes
additional info
Publisher Copyright: © 2024 authors. Published by the American Physical Society.
id
c9b00f97-9163-4991-9f6b-de3c43158f7c
date added to LUP
2024-10-31 11:21:43
date last changed
2025-10-14 10:55:39
@article{c9b00f97-9163-4991-9f6b-de3c43158f7c,
  abstract     = {{<p>Second-order phase transitions appear as a divergence in one of the linear response functions. For a system of correlated electrons, the relevant divergent response can and does involve many-particle observables, most famously the double occupancy. Generally, evaluating the linear response function of many-particle observables requires a many-particle generalization of the Bethe-Salpeter equation. However, here I show that the divergence of linear response functions in dynamical mean-field theory is governed by a two-particle Bethe-Salpeter equation, even for many-particle observables. The reason for this is that the divergence at the second-order phase transition is produced by the self-consistent feedback of the dynamical mean field.</p>}},
  author       = {{Van Loon, Erik G.C.P.}},
  issn         = {{2469-9950}},
  language     = {{eng}},
  month        = {{06}},
  number       = {{24}},
  publisher    = {{American Physical Society}},
  series       = {{Physical Review B}},
  title        = {{Second-order phase transitions and divergent linear response in dynamical mean-field theory}},
  url          = {{http://dx.doi.org/10.1103/PhysRevB.109.L241110}},
  doi          = {{10.1103/PhysRevB.109.L241110}},
  volume       = {{109}},
  year         = {{2024}},
}