Observation and analysis of the hyperfine structure of near-dissociation levels of the NaCscΣ+3state below the dissociation limit3

Observation of photoassociation of ultracold sodium and cesium at the asymptote Na (3S1/2) + Cs (6P1/2)

“…1 depicts schematically, the experiment was carried out in a dual-species Na-Cs apparatus; most of these details were described in our studies on the c 3 Σ + excited state of NaCs below the dissociation limit 3S 1/2 + 6P 3/2 . 52 Here, we present some key characteristics of the setup.…”

“…We have used the same simplified model, which was applied to the PA spectra for NaCs near the Na (3S 1/2 ) + Cs (6P 3/2 ) asymptote in our previous work. 52 The main idea was to consider 4 initially unperturbed levels belonging to the Hund's case "a" electronic states with symmetries of 1 Σ, 3 Σ, 1 Π, and 3 Π and to mix them with various fine and hyperfine mechanisms. The relative positions of these levels are fitted to get the best reproduction of the experimental spectrum; the coupling parameters are also slightly adjusted, but they maintain magnitudes close to the values at the atomic limit.…”

“…However, as the Franck-Condon factors (FCFs) of PA transitions are extremely small for heteronuclear molecules and the sensitivity of trap-loss detection is not sufficiently high, there were previously few reports on TLS for NaCs molecules. 51,52 Detailed studies on NaCs molecular TLS, especially for the mixed A 1 Σ + b 3 Π singlet-triplet states and for the molecular hyperfine structures, are required for many potential applications of ultracold polar molecules. 52,53 In this paper, we demonstrate the high-resolution trap-loss spectroscopy of ultracold polar NaCs molecules below the Na (3S 1/2 ) + Cs (6P 1/2 ) asymptote (corresponding to the cesium atomic D 1 line at 894 nm), which are induced by the PA of a dual-species Na-Cs magneto-optical trap (MOT) using a modulation spectroscopy technique.…”

“…51,52 Detailed studies on NaCs molecular TLS, especially for the mixed A 1 Σ + b 3 Π singlet-triplet states and for the molecular hyperfine structures, are required for many potential applications of ultracold polar molecules. 52,53 In this paper, we demonstrate the high-resolution trap-loss spectroscopy of ultracold polar NaCs molecules below the Na (3S 1/2 ) + Cs (6P 1/2 ) asymptote (corresponding to the cesium atomic D 1 line at 894 nm), which are induced by the PA of a dual-species Na-Cs magneto-optical trap (MOT) using a modulation spectroscopy technique. 52 12 rovibrational levels were observed, whose electronic components have a blended nature with prevailing A 1 Σ + and b 3 Π characters.…”

“…52,53 In this paper, we demonstrate the high-resolution trap-loss spectroscopy of ultracold polar NaCs molecules below the Na (3S 1/2 ) + Cs (6P 1/2 ) asymptote (corresponding to the cesium atomic D 1 line at 894 nm), which are induced by the PA of a dual-species Na-Cs magneto-optical trap (MOT) using a modulation spectroscopy technique. 52 12 rovibrational levels were observed, whose electronic components have a blended nature with prevailing A 1 Σ + and b 3 Π characters. The hyperfine structure of the highest observed ro-vibrational level is registered and analyzed.…”