Failure of Fermi Liquid Theory in Two and Three Dimensions

G. Baskaran

Sudhakar Yarlagadda, Susumu Kurihara

Subhro Bhattacharjee, Sung-Sik Lee, Yong Baek Kim

N. H. March

Many-body effects in jellium, M.P. Tosi solids with weak and strong electron correlations, P. Fulde ground and low-lying excited states of interacting electron systems - a survey and some critical analyses, B. Farid failure of Fermi liquid theory in two and three dimensions, G. Baskaran quantum phase transitions in electronic systems, T.R. Kirkpatrick and D. Belitz density matrices, density functional theory and quantum Monte Carlo calculations, N.H. March.

D. ter Haar

Gisia-Bano Beydaghyan

The question of the breakdown of Fermi liquid theory in two dimensions is examined in the context of perturbation theory for a dilute interacting Fermi gas. The quasiparticle interaction function, fic;u;, is calculated for such a system. The interaction function, calculated to second order in terms of the dimensionless coupling constant, shows various singularities. The most divergent terms appear in the cross channel, but cancel out leaving a much weaker singularity in the limit of two moment a approaching each other (0 —f 0 ). As in the case of the three dimensional Fermi gas, the Cooper channel contains a logarithmic singularity in the limit 0 —f 7r. This singularity can be summed and is known to be harmless to the structure of Fermi liquid theory. A different feature in two dimensions is the existence of such a singularity for 0 —p 0. This feature needs further investigation. Calculations have also been extended to a polarized Fermi gas and the result is equivalent to the unpolarized case and does not show any additional features. In conclusion, the results do not indicate the presence of strong divergences which could cause the breakdown of Fermi liquid theory in two dimensions for a dilute interacting Fermi gas.