Abstract: Measuring a magnetic gradient according to the present invention includes generating a beam of like atoms with magnetic sublevels, applying a first pulse of electro-magnetic radiation to the beam of atoms to create a coherent superposition of the magnetic sublevels in the atoms in which the superposition results in a plurality of beams following separate paths and in which at least two of the paths are arms of an interferometer, applying a second pulse of electromagnetic radiation to both beams of atoms a time T later with characteristics substantially similar to the first pulse and in which the product of the Rabi frequency and T now must equal ? (versus ?/2 in the first pulse), whereby the states of the atoms in the two arms of the interferometer are coherently interchanged and are redirected towards each other.

Abstract: Measuring a magnetic gradient according to the present invention includes generating a beam of like atoms with magnetic sublevels, applying a first pulse of electro-magnetic radiation to the beam of atoms to create a coherent superposition of the magnetic sublevels in the atoms in which the superposition results in a plurality of beams following separate paths and in which at least two of the paths are arms of an interferometer, applying a second pulse of electromagnetic radiation to both beams of atoms a time T later with characteristics substantially similar to the first pulse and in which the product of the Rabi frequency and T now must equal ? (versus ?/2 in the first pulse), whereby the states of the atoms in the two arms of the interferometer are coherently interchanged and are redirected towards each other.