  We analyze a tripod atom light coupling scheme characterized by two dark
states playing the role of quasi-spin states. It is demonstrated that by
properly configuring the coupling laser fields, one can create a lattice with
spin-dependent sub-wavelength barriers. This allows to flexibly alter the
atomic motion ranging from atomic dynamics in the effective brick-wall type
lattice to free motion of atoms in one dark state and a tight binding lattice
with a twice smaller periodicity for atoms in the other dark state. Between the
two regimes, the spectrum undergoes significant changes controlled by the laser
fields. The tripod lattice can be produced using current experimental
techniques. The use of the tripod scheme to create a lattice of degenerate dark
states opens new possibilities for spin ordering and symmetry breaking.
