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The system consists of layers with in average constant width and
rough interfaces. In the thermodynamic limit the numerical results
show that the system in two dimensions is insulator in the presence
of small roughness. However in three dimensions the system shows a
Metal-Insulator transition and possess a mobility edge. For three
dimensional superlattice the localization length follows a power-law
near the mobility edge $\xi(E) \sim (Ec - E)^{-\nu}$, where the
exponent is $\nu \simeq 0.9$. We also show that the existence of the
extended states in three dimensional superlattices cause a finite
dc-conductivity in the limit $M/L \rightarrow \infty$, where L is
the length and M is the width of the bar.
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