Atomic Looping

Jakob Reichel, W. Hänsel

Howard M. Wiseman

Electro-optical feedback can produce an in-loop photocurrent with arbitrarily low noise. This is not regarded as evidence of ``real'' squeezing because squeezed light cannot be extracted from the loop using a linear beam splitter. Here I show that illuminating an atom (which is a nonlinear optical element) with ``in-loop'' squeezed light causes line narrowing of one quadrature of the atom's fluorescence. This has long been regarded as an effect that can only be produced by squeezing. Experiments on atoms using in-loop squeezing should be much easier than those with conventional sources of squeezed light.

Alexey Tonyushkin, Mara Goff Prentiss

We experimentally demonstrate that an atom-optics kicked rotor can remove the interference signal due to chosen interferometer paths in a four-pulse de Broglie wave atom interferometer. The interferometer output is dominated by two degenerate spatial loops: the nonreciprocal “trapezoid” loop and the reciprocal “figure-8” loop. By applying the kicked rotor sequence at a particular time we suppressed the contribution of the “trapezoid” loop to the interferometer signal while preserving the contribution due to the “figure-8” loop. When the degeneracy is present, the interferometer is sensitive to both rotation and linear acceleration. When the degeneracy is lifted the interferometer is insensitive to linear acceleration, but still sensitive to rotation. The suppression of nonreciprocal loops in an atom interferometer is valuable for rotation sensing.

Valerie Jamieson

Richard G. Brewer, Erwin Louis Hahn

Alexey Tonyushkin, Mara Goff Prentiss

We experimentally demonstrate that an atom-optics kicked rotor can remove the interference signal due to chosen interferometer paths in a four-pulse de Broglie wave atom interferometer. The interferometer output is dominated by two degenerate spatial loops: the nonreciprocal ``trapezoid'' loop and the reciprocal ``figure-8'' loop. By applying the kicked rotor sequence at a particular time we suppressed the contribution of the ``trapezoid'' loop to the interferometer signal while preserving the contribution due to the ``figure-8'' loop. When the degeneracy is present, the interferometer is sensitive to both rotation and linear acceleration. When the degeneracy is lifted the interferometer is insensitive to linear acceleration, but still sensitive to rotation. The suppression of nonreciprocal loops in an atom interferometer is valuable for rotation sensing.