  We propose a scheme to create an effective magnetic field for ultra-cold
atoms in a planar geometry. The set-up allows the experimental study of
classical and quantum Hall effects in close analogy to solid-state systems
including the possibility of finite currents. The present scheme is an
extention of the proposal in Phys. Rev. Lett. 93, 033602 (2004) where the
effective magnetic field is now induced for three-level Lambda-type atoms by
two counterpropagating laser beams with shifted spatial profiles. Under
conditions of electromagentically induced transparency the atom-light
interaction has a space dependent dark state, and the adiabatic center of mass
motion of atoms in this state experiences effective vector and scalar
potentials. The associated magnetic field is oriented perpendicular to the
propagation direction of the laser beams. The field strength achievable is one
flux quantum over an area given by the transverse beam separation and the laser
wavelength. For a sufficiently dilute gas the field is strong enough to reach
the lowest Landau level regime.
