Husslein, Thomas and Fettes, Werner and Morgenstern, Ingo (1997) Comparison of calculations for the Hubbard model obtained with quantum-Monte-Carlo, exact, and stochastic diagonalization. INTERNATIONAL JOURNAL OF MODERN PHYSICS C, 8 (2). pp. 397-415. ISSN 0129-1831
Full text not available from this repository.Abstract
In this paper we compare numerical results for the ground state of the Hubbard model obtained by Quantum-Monte-Carlo simulations with results from exact and stochastic diagonalizations. We find good agreement for the ground state energy and superconducting correlations for both, the repulsive and attractive Hubbard model. Special emphasis lies on the superconducting correlations in the repulsive Hubbard model, where the small magnitude of the values obtained by Monte-Carlo simulations gives rise to the question, whether these results might be caused by fluctuations or systematic errors of the method. Although are notice that the Quantum-Monte-Carlo method has convergence problems for large interactions, coinciding with a minus sign problem, we confirm the results of the diagonalization techniques for small and moderate interaction strengths. Additionally we investigate the numerical stability and the convergence of the Quantum-Monte-Carlo method in the attractive case, to study the influence of the minus sign problem on convergence. Also here in the absence of a minus sign problem we encounter convergence problems for strong interactions.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | SYSTEMS; Hubbard model; minus sign; Quantum-Monte-Carlo; exact diagonalization; stochastic diagonalization; correlated electrons; superconductivity |
| Subjects: | 500 Science > 530 Physics |
| Divisions: | Physics > Institute of Theroretical Physics > Professor Morgenstern > Group Ingo Morgenstern |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 11 May 2023 08:58 |
| Last Modified: | 11 May 2023 08:58 |
| URI: | https://pred.uni-regensburg.de/id/eprint/50948 |
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