Measurement of atomic g factor ratios using laser cooled atoms

We have used pulsed laser excitation to create a spatially periodic coherence grating between adjacent magnetic sublevels of the ground state in a cloud of trapped Rb atoms. The light scattered from the grating exhibits Larmor oscillations in the presence of a magnetic field with the frequency defined by the energy level splitting between magnetic sublevels. We describe the progress in our measurements of the atomic g factor ratio using the F=3 to F’=4 transition in $^{85}$Rb and the F=2 to F’=3 in $^{87}$Rb. The current level of precision is $\sim$25 ppm achieved by acquiring data for about four hours. We describe studies of systematic effects due to fluctuating ambient magnetic fields and AC Stark shifts with the goal of achieving a precision of less than 1 ppm.