Dresden 2006 – wissenschaftliches Programm

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TT: Tiefe Temperaturen

TT 25: Correlated Electrons - Poster Session

TT 25.49: Poster

Mittwoch, 29. März 2006, 14:30–18:30, P1

Phase diagram of the Hubbard model with t-t′ hopping on the Bethe lattice — •M. Eckstein¹, M. Kollar¹, M. Potthoff², and D. Vollhardt¹ — ¹Theoretical Physics III, University of Augsburg — ²Institute of Theoretical Physics and Astrophysics, University of Würzburg

Recently an efficient method for solving hopping Hamiltonians on the Bethe lattice was developed [1]. For infinite coordination number this provides the dynamical mean-field equations for the Hubbard model with nearest-neighbor hopping t and next-nearest-neighbor hopping t′. We solve these equations using the self-energy functional approach [2] and compute the phase diagram. We find that t′ hopping strongly influences the Mott-Hubbard metal-insulator transition in the paramagnetic phase. Results for the antiferromagnetic phase, which is suppressed by t′ hopping, are also discussed.

[1] M. Eckstein et al., Phys. Rev. B 71, 235119 (2005); M. Kollar et al., Ann. Phys. 14, 642 (2005).

[2] M. Potthoff, Eur. Phys. J. B 32, 429 (2003).