Extended Data Fig. 3: Acceleration shift owing to lattice divergence a^ls.

In an auxiliary measurement, we observe a linear change in measured acceleration a^ls as a function of vertical position z. This is because of the differential AC Stark shift from the changing trap potential, ΔU(z), as the atoms are held in various positions along the diverging lattice potential. We observe good agreement between the analytic equation derived above, simulation and experiment. The bands correspond to 95% (2σ) confidence intervals.