Effects of Light Scattering and Collisions on a Single State Atom Interferometer

Scott Beattie, I. Y. Chan, Anantharaman Kumarakrishnan

M. Zhang

Atomic Kapitza-Dirac (KD) scattering in the classical standing wave of lights is widely used to make the laser-pulsed atom interferometers. In this theoretical work, we show that the dielectric nanoparticle can be used as a weak light source to generate atomic KD scattering and make atom interferometer. We consider a cavity system consisting of atoms and a single nanoparticle, where the nanoparticle is illuminated by the external laser pulses. Atoms and the cavity mirrors are not illuminated by the laser beam, so nanoparticle acts as a pulsed source to excite the cavity mode which non-resonantly excites atomic internal state and generates a weak KD scattering of atomic external motion. We use twice such scattering to split atomic path and consequently use two classical laser pulses to recombine the separated paths for generating the Ramsey-Bordé atom interferometer. This atom interferometer is entangled with the centre-of-mass motion of nanoparticle and could be developed to search the small nonclassicality of motional nanoparticle, because the cavity mode excitation is associated with nanoparticle's position relative to the node or antinode of that optical mode.

Grant W. Biedermann

James Stickney, Matthew B. Squires, James Scoville +2 more

The coherence time, and thus sensitivity, of trapped-atom interferometers that use nondegenerate gases are limited by the collisions between the atoms. An analytic model that describes the effects of collisions between atoms in an interferometer is developed. It is then applied to an interferometer using a harmonically trapped nondegenerate atomic gas that is manipulated with a single set of standing wave laser pulses. The model is used to find the optimal operating conditions of the interferometer and direct Monte Carlo simulation of the interferometer is used to verify the analytic model.

Frank A. Narducci

Hyosub Kim, Krzyzanowska, Katarzyna, Karl C. Henderson +3 more

We report a multiple-loop guided atom interferometer in which the atoms make 200 small-amplitude roundtrips, instead of one large single orbit. The approach is enabled by using ultracold 39K gas and a magnetic Feshbach resonance that can tune the s-wave scattering length across zero to significantly reduce the atom loss from cold collisions. This scheme is resilient against noisy environments, achieving 0.9 s interrogation time without any vibration noise isolation or cancellation. A form of quantum lock-in amplification can be used with the device to measure localized potentials with high sensitivity. We used this technique to measure the dynamic polarizability of the 39K ground state at 1064 nm. The interferometer may also be a useful approach to building a compact multiple-loop Sagnac atom interferometer for rotation sensing.