Self-consistency and the GW-approximation
(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:
https://lup.lub.lu.se/record/29032
- author
- Holm, Bengt LU
- supervisor
- opponent
-
- Shirley, Eric L.
- organization
- publishing date
- 1997
- 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 10:15:00
- 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
- 2016-04-04 11:06:48
- date last changed
- 2018-11-21 21:02:44
@phdthesis{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}}, 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}}, language = {{eng}}, publisher = {{B. Holm}}, school = {{Lund University}}, title = {{Self-consistency and the GW-approximation}}, year = {{1997}}, }