  The model of two electrons with Coulomb interaction on a two-dimensional (2D)
disordered lattice is considered. It is shown that the interaction can give a
sharp transition to delocalized states in a way similar to the Anderson
transition in 3D. The localized phase appears when the ratio of the Coulomb
energy to the Fermi energy becomes larger than some critical value dependent on
the disorder. The relation to the experiments on metal-insulator transition in
2D is also discussed.
