Large-Momentum-Transfer Atom Interferometers with μrad-Accuracy Using Bragg Diffraction.

Large-momentum-transfer (LMT) atom interferometers using elastic Bragg scattering on light waves are among the most precise quantum sensors to date. To advance their accuracy from the mrad to the μrad regime, it is necessary to understand the rich phenomenology of the Bragg interferometer, which differs significantly from that of a standard two-mode interferometer. We develop an analytic model for the interferometer signal and demonstrate its accuracy using comprehensive numerical simulations. Our analytic treatment allows the determination of the atomic projection noise limit of a LMT Bragg interferometer and provides the means to saturate this limit. It affords accurate knowledge of the systematic phase errors as well as their suppression by 2 orders of magnitude down to a few μrad using appropriate light-pulse parameters.