Fig. 4: Effects of ion motion in a 1000 ion Coulomb crystal at a motional temperature of 120 μK on spectroscopy of the clock transition.
From: Prospects of a thousand-ion Sn2+ Coulomb-crystal clock with sub-10−19 inaccuracy
a Histogram showing the number of collective motional normal modes binned by the motional mode frequency, which ranges from a minimum of 32 kHz up to a maximum of 1.419 MHz. b Histogram showing the number of ions binned by the Debye-Waller factor due to secular motion, which relates the Rabi frequency for driving the clock transition in an ion at rest with the Rabi frequency for an ion undergoing secular motion. c Calculated spectrum of the clock transition probed using Rabi spectroscopy with a probe duration of 1 ms and a laser intensity that maximizes the on-resonance transition probability, averaged over all of the ions. The inset is an enlargement of the region near the atomic transition frequency, showing the carrier at zero detuning and a few discrete motional sidebands. For larger detunings shown in the main plot, the motional sidebands overlap in frequency to form broad bands.
