Reflection of cold atoms from an array of current-carrying wires

We report the realization of a new type of magnetostatic mirror for slowly moving atoms which comprises a planar array of parallel wires alternately c arrying electric current in opposite directions. One of the features of thi s atomic mirror is that the magnetic field may be readily varied, switched or modulated by altering the current in the wires. Reflection signals close to 100% at a pulsed current of 3 A are demonstrated for a beam of free-fal ling laser-cooled cesium atoms at normal incidence. The current dependence of the reflection signals exhibits structure which is associated with the s equential onset of reflection of cesium 6(2)S(1/2), F = 4 atoms in the m = +4, +3, +2 and +1 magnetic states. Measurements of the spatial distribution of the reflected atoms indicate the reflection is predominantly specular a t currents of 3 A.