Link auxiliary field method in the extended Hubbard model.

The aim of this work is to generalize the method of Hubbard fields in fermion quantum Monte Carlo simulations to the case of link fields. The introduced Hubbard link fields play the role of the interaction fields responsible for the attraction and repulsion of electronic excitations at the nodes. Such improvements lead to a number of advantages concerning thermalization time, autocorrelations, metastable states, and probability distributions of the quantities. It is demonstrated that computations using five fields are more stable and reliable in the case of energy observables.