Communications in Theoretical Physics
Calculation of the Binding Energy in the One-Dimensional Hubbard Model by the VMC Method
Yongjun Liu, Jinming Dong, Chang-De Gong
Abstract
Using variational Monte-Carlo method and choosing an antiferromagnetic trial wave function, we have calculated the binding energies just off half-filling in one-dimensional Hubbard chains. We found the binding for the lattice length N being less than 40 in the degenerate case, but no binding at all in the non-degenerate case. However, with lattice length increasing gradually, difference between the two cases becomes smaller and smaller. Finally, there is no binding at all no matter whether or not the chains have a degeneracy at the Fermi level in the non-interacting limit. It may be an indication of the independence of the final calculation results on the boundary conditions for the large enough system or in thermodynamic limit.