Off-diagonal Wave Function Monte Carlo Method of Hubbard model I

Abstract

We propose a Monte Carlo method, which is a hybrid method of the quantum Monte Carlo method and variational Monte Carlo theory, to study the Hubbard model. The theory is based on the off-diagonal and the Gutzwiller type correlation factors which are taken into account by a Monte Carlo algorithm. In the 4x4 system our method is able to reproduce the exact results obtained by the diagonalization. An application is given to investigate the half-filled band case of two-dimensional square lattice. The energy is favorably compared with quantum Monte Carlo data.
Article Outline

1. Introduction
2. Hamiltonian and Wave Functions
3. Comparison with Exact Results and Other QMC Methods
4. Results for the Half-Filled Case
5. Summary

Acknowledgements
References

Keywords: two-dimensional Hubbard model, Monte Carlo method, off-diagonal functions

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