Yang A, Botsi S, Kumar S, Pal SB, Lam MM, Čepaitė I, Laugharn A, Dieckmann K. Singlet Pathway to the Ground State of Ultracold Polar Molecules.
Phys Rev Lett 2020;
124:133203. [PMID:
32302184 DOI:
10.1103/physrevlett.124.133203]
[Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 03/09/2020] [Indexed: 06/11/2023]
Abstract
Starting from weakly bound Feshbach molecules, we demonstrate a two-photon pathway to the dipolar ground state of bi-alkali molecules that involves only singlet-to-singlet optical transitions. This pathway eliminates the search for a suitable intermediate state with sufficient singlet-triplet mixing and the exploration of its hyperfine structure, as is typical for pathways starting from triplet dominated Feshbach molecules. By selecting a Feshbach state with a stretched singlet hyperfine component and controlling the laser polarizations, we assure coupling to only single hyperfine components of the A^{1}Σ^{+} excited potential and the X^{1}Σ^{+} rovibrational ground state. In this way an ideal three level system is established, even if the hyperfine structure is not resolved. We demonstrate this pathway with ^{6}Li^{40}K molecules, and discuss its application to other important molecular species.
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