We demonstrate quantum control and precision spectroscopy of a single molecular ion via quantum logic spectroscopy . In our experiment, we prepare a molecular ion in pure quantum states via projective measurements. The state of the molecule can subsequently be coherently manipulated, as demonstrated by Rabi oscillations between magnetic sublevels of rotational states in either the same or distinct rotational manifolds. We use one continuous-wave laser and one frequency comb , both far off-resonant from molecular transitions, to manipulate the molecule. With the frequency comb, the frequencies of several rotational transitions in the molecule are measured with precision better than 1 part-per-billion. Our setup enables coherent control and precision measurement of a vast number of molecular ion species while only changing the source of the molecules.
This work was supported by the US Army Research Office and the NIST quantum information program. C. Kurz acknowledges support from the Alexander von Humboldt foundation. P. N. Plessow acknowledges support by the state of Baden-Wurttemberg through bwHPC.
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Prof. Yiheng Lin did the Ph. D with Dr. David Wineland in NIST and the post-doc. with Prof. Cindy Regal in JILA and joined the USTC as a faculty.