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TT: Tiefe Temperaturen
TT 7: Supraleitung: Theorie
TT 7.3: Talk
Tuesday, March 27, 2001, 10:30–10:45, J
Low-density extension for the electron gas with attractive interaction — •Markus Himmerich and Martin Letz — Insitut für Physik, Johannes Gutenberg-Universität, Staudinger Weg 7, D-55099 Mainz, Germany
The unusual short coherence length of the Cooper pairs in high-Tc-materials and other unconventional superconducting compounds points towards a strong effective electron-electron interaction. The simplest model to study superconductivity is the attractive Hubbard model. In its weak coupling 3D limit it shows superconductivity according to the BCS theory. As a first step towards a systematic strong coupling low-density extension of the BCS theory we include three-particle terms with its complete dynamics [1]. Via the three-particle terms we calculate a weakening of the effective two-particle interaction as a systematic correction at low densities.
[1] M. Himmerich and M. Letz cond-mat/0009262