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TT: Tiefe Temperaturen
TT 15: Korrelierte Elektronensysteme Theorie I
TT 15.4: Vortrag
Dienstag, 27. März 2001, 16:30–16:45, H
Electron- versus hole-doping in the 2D t-t′ Hubbard model — •Carsten Honerkamp — Institut für Theoretische Physik, ETH Hönggerberg, CH-8093 Zürich, Schweiz
We compare the one-loop RG flow to strong coupling of the electronic interactions in the electron- and hole-doped 2D t-t′-Hubbard model. Using a numerical N-patch scheme (N=32… 96) we show that in the electron-doped case with decreasing electron density there is a rapid transition from a dx2−y2-wave pairing regime with small characteristic energy scale to a nesting regime with strong antiferromagnetic tendencies and higher energy scales. This contrasts with the hole-doped side discussed recently (Honerkamp et al. cond-mat/9912358, to be published in Phys.Rev. B) which exhibits a broad parameter region where the RG flow suggests a truncation of the Fermi surface with formation of an insulating spin liquid at the saddle points. The quasiparticle scattering rates have different angular dependences around the Fermi surface and show different locations and properties of the hot spots.