Advanced

Self-consistency and the GW-approximation

Holm, Bengt LU (1997)
Abstract
The effects of self-consistency in the GW-approximation are studied. The $GWA$ is known to describe the electronic properties of a wide range of materials very well. However, the calculations made so far have not taken into account the issue of self-consistency, which is implied in the original formulation of the $GWA$. The role of self-consistency is investigated by calculating the electronic self-energy of the homogeneous electron gas, using the $GWA$ with different levels of self-consistency.



It is demonstrated that the physical properties produced by a fully self-consistent scheme do not agree well with experiment. The necessity of vertex corrections is pointed out. However, it is shown that the total energies... (More)
The effects of self-consistency in the GW-approximation are studied. The $GWA$ is known to describe the electronic properties of a wide range of materials very well. However, the calculations made so far have not taken into account the issue of self-consistency, which is implied in the original formulation of the $GWA$. The role of self-consistency is investigated by calculating the electronic self-energy of the homogeneous electron gas, using the $GWA$ with different levels of self-consistency.



It is demonstrated that the physical properties produced by a fully self-consistent scheme do not agree well with experiment. The necessity of vertex corrections is pointed out. However, it is shown that the total energies resulting from this scheme, calculated through the Galitskii-Migdal formula, agree very well with existing Monte-Carlo data. Numerical evidence also confirms that the scheme of full self-consistency fulfills the criteria of a so-called conserving approximation.



Further, a scheme of partial self-consistency is presented and investigated. The application of this scheme to a real system lies within reach of present day computer capability. It is found that the partial self-consistency gives a reasonable description of most physical properties. (Less)
Please use this url to cite or link to this publication:
author
opponent
  • Shirley, Eric L.
organization
publishing date
type
Thesis
publication status
published
subject
keywords
Matematisk och allmän teoretisk fysik, thermodynamics, Spectral Function, Greens functions, Self-energy, classical mechanics, Mathematical and general theoretical physics, Quasiparticle., quantum mechanics, relativity, statistical physics, gravitation, klassisk mekanik, kvantmekanik, relativitet, statistisk fysik, termodynamik, Fysicumarkivet A:1997:Holm
pages
122 pages
publisher
B. Holm
defense location
Physics bldg, Hall B
defense date
1997-02-28 10:15
external identifiers
  • Other:ISRN: LUNFD6/(NFTF-1031)/1-122/(1997)
language
English
LU publication?
yes
id
0d4d373c-8a25-41d1-ad54-a0c6b0ffea39 (old id 29032)
date added to LUP
2007-06-12 13:45:49
date last changed
2016-09-19 08:45:08
@misc{0d4d373c-8a25-41d1-ad54-a0c6b0ffea39,
  abstract     = {The effects of self-consistency in the GW-approximation are studied. The $GWA$ is known to describe the electronic properties of a wide range of materials very well. However, the calculations made so far have not taken into account the issue of self-consistency, which is implied in the original formulation of the $GWA$. The role of self-consistency is investigated by calculating the electronic self-energy of the homogeneous electron gas, using the $GWA$ with different levels of self-consistency.<br/><br>
<br/><br>
It is demonstrated that the physical properties produced by a fully self-consistent scheme do not agree well with experiment. The necessity of vertex corrections is pointed out. However, it is shown that the total energies resulting from this scheme, calculated through the Galitskii-Migdal formula, agree very well with existing Monte-Carlo data. Numerical evidence also confirms that the scheme of full self-consistency fulfills the criteria of a so-called conserving approximation.<br/><br>
<br/><br>
Further, a scheme of partial self-consistency is presented and investigated. The application of this scheme to a real system lies within reach of present day computer capability. It is found that the partial self-consistency gives a reasonable description of most physical properties.},
  author       = {Holm, Bengt},
  keyword      = {Matematisk och allmän teoretisk fysik,thermodynamics,Spectral Function,Greens functions,Self-energy,classical mechanics,Mathematical and general theoretical physics,Quasiparticle.,quantum mechanics,relativity,statistical physics,gravitation,klassisk mekanik,kvantmekanik,relativitet,statistisk fysik,termodynamik,Fysicumarkivet A:1997:Holm},
  language     = {eng},
  pages        = {122},
  publisher    = {ARRAY(0xb2da788)},
  title        = {Self-consistency and the GW-approximation},
  year         = {1997},
}