On the dynamic structure factor for the electron gas

We cast the well-known electron gas model into a path integral version, then studied its dynamic structure factor S(q,q0 ) systematically. Our study shows that qc defined in RPA not only is the threshold for a bare plasmon, but also in general the one for any number of renormalized plasmons. We have particularly studied large momentum transfer case (q > qc). We proved that the self-energy correction appearing in the pertinent Green functions of S(q,q0 ) vanishes. Those theoretical results indicate that the first peak in the fine structure of S(q,q 0 ) observed in experiments for large q (~ 1.5 qf) neither comes from a plasmon nor occurs due to a particle life-time or a self-energy correction. Our explanation for the first peak is that it arises from a strong correlation between single-pair excitation and multi-pair excitation involving only a few pairs (CSF). This conclusion was reached following a qualitative study of a two particle irreducible part of diagrams; some further elaborate numerical calculations are needed to confirm this hypothesis. An approximate, but nevertheless closed, formula for summing a set of screened ladder diagram (SLD), which describes the strongest correlation between single-pair and a few (two) pairs, is presented.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Physics

Year dc:date

2011

Author dc:creator

• Ren, De-Ming

Contributors dc:contributor

• Pines, David

• electron gas
• renormalized plasmons
• large momentum transfer
• Green's functions

Statement dc:rights

• 1987 De-Ming Ren

Language dc:language

en

Identifier

3473946

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/25218