Behavior of the spin-spin correlation function through the metal-insulator transition

As the typical example of the correlation driven metal-insulator transition occurs in the one-dimensional Hubbard model, we consider this model as the starting point of our study. Using an extended bosonization technique developed previously by us [1] we calculate, for the first time, the spin-spin correlation function in both the insulating and metallic phase, to characterize the crossover between these two behaviors, and thus to describe the spin properties of the metal-insulator transition.