Scaling behavior in the current-voltage characteristic of one- and two-dimensional arrays of small metallic islands.

We have measured the current-voltage ({ital I}-{ital V}) characteristics of one- and two-dimensional arrays of normal metal islands linked by small tunnel junctions. The tunneling resistance is large compared to the resistance quantum, and a ground plane reduces the screening length to much less than the interisland spacing. At temperatures well below the island charging energy, we find a threshold voltage {ital V}{sub {ital T}} below which little current flows. For {ital V}{gt}{ital V}{sub {ital T}}, {ital I} scales as ({ital V}/{ital V}{sub {ital T}}{minus}1){sup {zeta}} where {zeta}=1.36{plus_minus}0.1 (1D) and 1.80{plus_minus}0.16 (2D). We interpret this behavior as a dynamic critical phenomenon.