## Abstract

We present a numerically stable Quantum Monte Carlo algorithm to calculate zero-temperature imaginary-time Green functions G(r, τ) for Hubbard type models. We illustrate the efficiency of the algorithm by calculating the on-site Green function G(r = 0, τ) on 4 × 4 to 12 × 12 lattices for the two-dimensional half-filled repulsive Hubbard model at U/t = 4. By fitting the tail of G(r = 0, τ) at long imaginary time to the form e^{-τΔε}, we obtain a precise estimate of the charge gap: Δ_{c} = 0.67±0.02 in units of the hopping matrix element. We argue that the algorithm provides a powerful tool to study the metal-insulator transition from the insulator side.

Original language | English |
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Pages (from-to) | 189-194 |

Number of pages | 6 |

Journal | journal of the physical society of japan |

Volume | 65 |

Issue number | 1 |

DOIs | |

Publication status | Published - 1996 |

Externally published | Yes |

## Keywords

- Hubbard gap
- Hubbard model
- Quantum Monte Carlo
- Zero-temperature Green functions

## ASJC Scopus subject areas

- Physics and Astronomy(all)