  Nonequilibrium wetting transitions are observed in Monte Carlo simulations of
a kinetic spin system in the absence of a detailed balance condition with
respect to an energy functional. A nonthermal model is proposed starting from a
two-dimensional Ising spin lattice at zero temperature with two boundaries
subject to opposing surface fields. Local spin excitations are only allowed by
absorbing an energy quantum (photon) below a cutoff energy E_c. Local spin
relaxation takes place by emitting a photon which leaves the lattice. Using
Monte Carlo simulation nonequilibrium critical wetting transitions are observed
as well as nonequilibrium first-order wetting phenomena, respectively in the
absence or presence of absorbing states of the spin system. The transitions are
identified from the behavior of the probability distribution of a suitably
chosen order parameter that was proven useful for studying wetting in the
(thermal) Ising model.
