  Quantum phases with unusual symmetries may play a key role for the
understanding of solid state systems at low temperatures. We propose a
realistic scenario, well in reach of present experimental techniques, which
should permit to produce a stationary quantum state with $d_{x^2-y^2}$-symmetry
in a two-dimensional bosonic optical square lattice. This state, characterized
by alternating rotational flux in each plaquette, arises from driven tunneling
implemented by a stimulated Raman scattering process. We discuss bosons in a
square lattice, however, more complex systems involving other lattice
geometries appear possible.
