Atomic quasi-Bragg-diffraction in a magnetic field

We report on a technique to split an atomic beam coherently with an easily adjustable splitting angle. In our experiment metastable helium atoms in the |{1s2s}S31M=1⟩ state diffract from a polarization gradient light field formed by counterpropagating σ+ and σ− polarized laser beams in the presence of a homogeneous magnetic field. In the near-adiabatic regime, energy conservation allows the resonant exchange between magnetic energy and kinetic …