Grid states form a discrete set of mixed quantum states that can be described
by graphs. We characterize the entanglement properties of these states and
provide methods to evaluate entanglement criteria for grid states in a
graphical way. With these ideas we find bound entangled grid states for
two-particle systems of any dimension and multiparticle grid states that
provide examples for the different aspects of genuine multiparticle
entanglement. Our findings suggest that entanglement theory for grid states,
although being a discrete set, has already a complexity similar to the one for
general states.Comment: 6 pages, 4 figures, v2: small changes, final versio
