Quantum Monte Carlo simulations of Hubbard type models
- Universitaet Wuerzburg (Germany)
The authors present a review of recent Quantum Monte-Carlo results for one- and two-dimensional Hubbard models. In one-dimension spectral properties are calculated with the maximum entropy method. At small doping, the one-particle excitations are characterized by a dispersive cosine-like band. Two different velocities for charge and spin-excitations are obtained which lead to a conformal charge c=0.98{+-}0.05. In two-dimensions, the authors concentrate on two methods to detect superconducting ground states without prior knowledge of the symmetry of the underlying pair-pair correlations: flux quantization and the temperature derivative of the superfluid density. Both methods are based on extensions of quantum Monte-Carlo algorithms to incorporate magnetic fields. The main results include numerical data which (a) confirm the Kosterlitz-Thouless transition in the attractive Hubbard model; (b) show the absence of superconductivity in the quarter filled repulsive Hubbard model; and finally (c) show no sign of a Kosterlitz-Thouless type transition in the three-band Hubbard model up to {beta}t{sub pd} = 12.5 and hole doping {delta} = 0.25.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 102564
- Report Number(s):
- CONF-9309321--
- Journal Information:
- Journal of Low Temperature Physics, Journal Name: Journal of Low Temperature Physics Journal Issue: 1-2 Vol. 95; ISSN 0022-2291; ISSN JLTPAC
- Country of Publication:
- United States
- Language:
- English
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