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TT: Tiefe Temperaturen
TT 25: Postersitzung III: Pinning und Vortexdynamik, Massive HTSL, Bandleiter, Transporteigenschaften in HTSL, SL dünner Filme, Elektronen und Phononen in HTSL, Tunneln, Borkarbide, Quantenphasen und Metall-Isolator-Überg
änge, Anwendungen, Sonstiges
TT 25.63: Poster
Thursday, March 29, 2001, 14:30–17:00, Rang S\ 3
Examination of a t1-t2-Hubbard model with RG methods — •Kim Louis, Claudius Gros, and Vincente Alvarez — Universität des Saarlandes, 66041 Saarbrücken
This poster is to present examinations of a Hubbard model (the results can also be applied to ladders) with both nearest and next nearest neighbour interaction in weak coupling analyzed by renormalization group (RG) methods. The aim of this ist to determine the phase (according to the number of gapless modes) for various dopings and hopping parameters. The main deviation from preceding articles (e.g. L. Balents and M. Fisher, Phys. Rev. B 57, 12133 (1996)) is the inclusion of nongeneric couplings and the consideration of the change of the Fermi wave vector caused by the RG-flow of the chemical potential. This change was found to be proportional to (v2/v1−1)U, where v1, v2 are the two Fermi velocities.