Dresden 2006 – wissenschaftliches Programm
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TT: Tiefe Temperaturen
TT 25: Correlated Electrons - Poster Session
TT 25.43: Poster
Mittwoch, 29. März 2006, 14:30–18:30, P1
Variational cluster approach to superconducting and antiferromagnetic phases in hole- and electron-doped cuprates — •Markus Aichhorn1,2, Enrico Arrigoni1, Michael Potthoff2, and Werner Hanke2 — 1Institute for Theoretical and Computational Physics, Graz University of Technology — 2Institute for Theoretical Physics, University of Würzburg
Using the recently proposed Variational Cluster Approach (VCA), we study the competition between d-wave superconductivity and antiferromagnetism in hole- and electron-doped cuprates. In both cases, our thermodynamic consistent results for the t-t’-U Hubbard model suggest the occurrence of phase separation into a mixed antiferromagnetic-superconducting phase at low doping and a pure superconducting phase at higher doping, although the energy scale for phase separation is an order of magnitude smaller on the electron-doped side. We argue that this can explain the different pseudogap and superconducting transition scales in hole- and electron-doped materials. The cluster calculations reproduce qualitatively the ground-state phase diagram of high-temperature supercondutors. In particular, they include salient features such as the enhanced robustness of the anitferromagnetic phase for electron-doping, compared to the hole-doped case.