Decoherence and dynamics in continuous 3D-cooled atom interferometry
We study decoherence in continuously cooled atom interferometers by performing Raman-Ramsey fringe measurements in a continuous beam of 3D-sub-Doppler-cooled rubidium atoms. The atom beam is produced by a two-stage cold atom source that is designed to mitigate the decoherence of atomic interference caused by cooling induced fluorescence. The atom beam source produces a collimated beam of over 109 atoms/s that is cooled by polarization gradient cooling to temperatures as low as 14 µK. We infer the potential performance of this atom beam source in a cold-atom gyroscope and use numerical models of motion in 6 degrees of freedom to study the expected performance on dynamic platforms.
Summary In this abstract, we propose a new finite-difference scheme for solving wave equations. This scheme splits the multidimensional system into different directions and solves each direction implicitly. Unlike most splitting methods in the literature which produce numerical anisotropy in diagonal directions, this method gives perfect circular impulse responses and allows lateral velocity variations. In this paper, we prove that the proposed scheme is unconditionally stable. In the numerical examples, we show some impulse response tests and compare them with the results from some high-order explicit finite-difference methods. The new method allows larger time step and requires less memory storage during the reverse time