AN EXACT METHOD TO SOLVE THE DILUTED EXTENDED HUBBARD-MODEL

In this paper, we report a new method to find an exact solution of the extended Hubbard Hamiltonian for systems with a low electronic density. This method is based on mapping the original problem onto a tight-binding case in a higher dimensional space, which can be solved exactly. For one- and two-dimensional systems, the local pairing problem of two electrons with anti-parallel spins is analyzed by looking at the binding energy and the coherence length for different interaction regimes. This method can be applied to study the electronic correlation in non-periodic systems.