Many-body effects in the thermodynamic properites of Fermi liquids and the electron-phonon system and in the excitation spectrum of liquid 4HE

In this thesis I study two separate topics in many-body physics. In the first part I consider many-body effects in the thermodynamic properties of Fermi liquids and of the electron-phonon system. Using normal liquid 3He as an example, I show that the T3lnT corrections due to spin fluctuations account for the finite temperature corrections to the leading term in the specific heat. I also calculate and compare the statistical and the dynamical quasiparticle spectra and show that differences between them partially account for the discrepancy between the present and previous results. Spin fluctuation parameters determined from fits to specific heat of UPt3 and UA12 are examined and applicability of simple spin-fluctuation models to these systems is discussed. In addition I consider the T3lnT contributions to the specific heat of metals due to the electron-phonon coupling and show how they may be viewed as being analogous to those from spin fluctuations. In the second part of the thesis I review the application of polarization potential theory to the description of the excitations of liquid 4He at low temperature and I use recent experimental results to determine the parameters in the theory. I calculate the dispersion curve in the absence of dynamic mode-mode coupling and discuss the results.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Physics

Year dc:date

2011

Author dc:creator

• Coffey, Dermot

Contributors dc:contributor

• Pethick, C.J.
• Pines, David

• many-body
• thermodynamics
• Fermi liquids
• electron-phonon system
• liquid 4He
• quasiparticle spectra

Statement dc:rights

• 1986 Dermot Coffey

Language dc:language

en

Identifier

1001002

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/25227