Frequency-comb spectroscopy on pure quantum states of a single molecular ion.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 32217722.
- Also identified by DOI 10.1126/science.aba3628 and PMC identifier 10652508.
- No licence information is recorded for this record.
- Because redistribution is not established, this page shows the abstract only. Follow the links below for the full text.
Abstract
Spectroscopy is a powerful tool for studying molecules and is commonly performed on large thermal molecular ensembles that are perturbed by motional shifts and interactions with the environment and one another, resulting in convoluted spectra and limited resolution. Here, we use quantum-logic techniques to prepare a trapped molecular ion in a single quantum state, drive terahertz rotational transitions with an optical frequency comb, and read out the final state nondestructively, leaving the molecule ready for further manipulation. We can resolve rotational transitions to 11 significant digits and derive the rotational constant of <sup>40</sup>CaH<sup>+</sup> to be <i>B</i> <sub>R</sub> = 142 501 777.9(1.7) kilohertz. Our approach is suited for a wide range of molecular ions, including polyatomics and species relevant for tests of fundamental physics, chemistry, and astrophysics.