ATOM INTERFEROMETRY Annual progress report to RLE

Introduction: deBroigle’s 1924 suggestion that material particles such as atoms should have wave properties was arguably the key that unlocked quantum mechanics two years later. Starting in the mid 1980’s, workers in the new field of atom optics put this suggestion to use by developing ways to manipulate atoms as waves that can be diffracted and focussed. Our lab combined three atom gratings to create an interferometer in which atomic deBroglie-waves are coherently split and separated by a metal foil before they recombine and produce interference fringes. Because our atomic beam deBroglie wavelength is only 1/5 of an Angstrom (20,000 times smaller than the wavelength of blue light), the fringe pattern is an extremely sensitive indicator of any perturbation to the interferometer. Our ability to accurately measure interactions that displace the deBrogliewave phase has led to qualitatively new measurements in atomic and molecular physics, fundamental tests of quantum mechanics and new ways to measure accelerations and rotation.