  Recently, significant interest has emerged in fabricated systems that mimic
the behavior of geometrically-frustrated materials. We present the full
realization of such an artificial spin ice system on a two-dimensional kagome
lattice and demonstrate rigid adherence to the local ice rule by directly
counting individual pseudo-spins. The resulting spin configurations show not
only local ice rules and long-range disorder, but also correlations consistent
with spin ice Monte Carlo calculations. Our results suggest that dipolar
corrections are significant in this system, as in pyrochlore spin ice, and they
open a door to further studies of frustration in general.
