Regensburg 2000 – wissenschaftliches Programm

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TT: Tiefe Temperaturen

TT 17: Postersitzung II: Pinning und Vortexdynamik (1-8), Supraleitung: Theorie (9-13), Korrelierte Elektronen (14-48), Niederdimensionale Systeme (49-68), Quantenflüssigkeiten (69-75)

TT 17.38: Poster

Mittwoch, 29. März 2000, 14:30–18:00, A

Single hole dynamics in the t-J model — •Michael Brunner, Fakher Assaad, and Alejandro Muramatsu — Institut für Theoretische Physik III, Universität Stuttgart, Pfaffenwaldring 57, 70550 Stuttgart

We present results for the single hole excitation spectrum in the t-J model at half filling and T=0 for values of J/t ranging from 0.4 to 4. The results are obtained by a recently developed Quantum Monte Carlo algorithm. We consider the single chain, two- and three-leg ladders and the two-dimensional square lattice, where the largest lattices are 24 × 24 lattice sites. Additional to the spectral function and the density of states, we give results for the quasiparticle weight. We show, that the numerical results in two dimension agree quantitatively with series expansions [1]. In the two- and three-leg ladder, the lower edge of the spectral function can be partly accurately described by the strong coupling limit. The quasiparticle weight in two dimensions and in the two-leg ladder is finite for the considered values of J/t, whereas in 1D we find a vanishing quasiparticle weight. In the three-leg ladder, we find a very small quasiparticle weight, that is possibly vanishing in the thermodynamic limit.

[1] C. J. Hamer et al , Phys. Rev. B 58, 15508 (1998)