Bound states of two electrons described by the<i>t</i>-<i>J</i>model

Abstract

A detailed study of the behavior of two electrons in the square lattice is presented in which the dynamics of the electronic pair is described by the t-J model. The conditions for the formation of bound states, pair correlation functions, and the energy spectra are obtained. The analysis is extended to the Cooper problem, i.e., to the study of the wave function of two electrons above the filled Fermi sea. Finally, the quantitative relationship between the t-J model and the one-band Hubbard model is numerically investigated for the two-electron problem.