Mott transition in quasi-one-dimensional systems

We report the application of the density-matrix renormalization-group method to a spatially anisotropic two-dimensional Hubbard model at half filling. We find a deconfinement transition induced by the transverse hopping parameter t(y) from an insulator to a metal. Therefore, if t(y) is fixed in the metallic phase, increasing the interaction U leads to a metal-to-insulator transition at a finite critical U. This is in contrast to the weak-coupling Hartree-Fock theory which predicts a nesting-induced antiferromagnetic insulator for any U > 0.