  Motivated by the recent experimental observation of a Mott insulating state
for the layered Iridate Na2IrO3, we discuss possible ordering states of the
effective Iridium moments in the presence of strong spin-orbit coupling and a
magnetic field. For a field pointing in the [111] direction - perpendicular to
the hexagonal lattice formed by the Iridium moments - we find that a
combination of Heisenberg and Kitaev exchange interactions gives rise to a rich
phase diagram with both symmetry breaking magnetically ordered phases as well
as a topologically ordered phase that is stable over a small range of coupling
parameters. Our numerical simulations further indicate two exotic multicritical
points at the boundaries between these ordered phases.
