GRAND-CANONICAL QUANTUM MONTE-CARLO METHODS - AN APPLICATION TO THE 1D HUBBARD-MODEL

We present a quantum Monte Carlo (QMC) method for the evaluation of th e partition functions of interacting electron systems. The theoretical framework is based on the functional integral formulation and uses th e discrete Hubbard-Stratonovich transformation. We are able to obtain stable simulation results for the low-temperature physical properties of the 1D Hubbard model by employing the stratified matrix decompositi on technique. The temperature dependence of the charge and the spin su sceptibilities are calculated. In addition, the charge and the spin st ructure factors, as well as the momentum distribution functions, are c alculated for the cases of half-filling and other fillings of the 1D H ubbard model.