  We investigate the many-body quantum states of a laser-driven gas of Rydberg
atoms confined to a large spacing ring lattice. If the laser driving is much
stronger than the van-der-Waals interaction among the Rydberg sates, these
many-body states are collective fermionic excitations. The first excited state
is a spin-wave that extends over the entire lattice. We demonstrate that our
system permits to study fermions in the presence of disorder although no
external atomic motion takes place. We analyze how this disorder influences the
excitation properties of the fermionic states. Our work shows a route towards
the creation of complex many-particle states with atoms in lattices.
