Regensburg 2004 – wissenschaftliches Programm
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TT: Tiefe Temperaturen
TT 24: Postersitzung III: Korrelierte Elektronen, ”Orbital Physics”
TT 24.25: Poster
Mittwoch, 10. März 2004, 14:30–19:00, Poster A
Stability of metallic stripes in the extended one-band Hubbard model — •Goetz Seibold1 and Jose Lorenzana2 — 1Lehrstuhl Theoretische Physik, BTU Cottbus, 03013 Cottbus, Germany — 2Dip. di Fisica, Universita di Roma ’La Sapienza’, 00185 Roma, Italy
Based on an unrestricted Gutzwiller approximation (GA) we investigate the stripe orientation and periodicity in an extended one-band Hubbard model. A negative ratio between next-nearest and nearest neighbor hopping t′/t, as appropriate for cuprates, favors partially filled (metallic) stripes for both vertical and diagonal configurations. At around optimal doping diagonal stripes, site centered (SC) and bond centered (BC) vertical stripes become degenerate suggesting strong lateral and orientational fluctuations. We find that within the GA the resulting phase diagram is in agreement with experiment whereas it is not in the Hartree-Fock approximation due to a strong overestimation of the stripe filling. Results are in agreement with previous calculations within the three-band Hubbard model but with the role of SC and BC stripes interchanged.