High-intensity two-frequency photoassociation spectroscopy of a weakly bound molecular state: Theory and experiment

Abstract

We investigate two-frequency photoassociation of a weakly bound molecular state, focusing on a regime where the AC Stark shift is comparable to the halo-state energy. In this "high-intensity" regime, we observe features absent in low-intensity two-frequency photoassociation. We experimentally measure the spectra of 86 Sr atoms coupled to the least bound state of the 86 Sr2 ground electronic channel through an intermediate electronically excited molecular state. We compare the spectra to a simple three-level model that includes a two-frequency drive on each leg of the transition. With numerical solution of the time-dependent Schrödinger equation, we show that this model accurately captures (1) the existence of experimentally observed satellite peaks that arise from nonlinear processes, (2) the locations of the two-photon peak in the spectrum, including AC Stark shifts, and (3) in some cases, spectral lineshapes. To better understand these numerical results, we develop an approximate treatment of this model, based on Floquet and perturbation theory, that gives simple formulas that accurately capture the halo-state energies. We expect these expressions to be valuable tools to analyze and guide future two-frequency photoassociation experiments. arXiv:1812.11682v2 [cond-mat.quant-gas]

Full optical preparation of an absolute ground-state ultracold CsYb molecule via laser-assisted self-induced Feshbach resonance

“…The preparation of ultracold molecules is still a challenging and attractive topic. Many ultracold molecular species were prepared in experiments, such as alkali-metal molecules Li 2 [8], Na 2 [9,10], K 2 [11,12], Rb 2 [13], Cs 2 [14], NaLi [15], NaK [16], NaRb [17], NaCs [18], CsK [19], KRb [20,21] and RbCs [22], alkaline-earth metals, lanthanide and actinide molecules Ca 2 [23], Sr 2 [24], RbSr [25] and CsYb [26]. The preparation methods of ultracold molecules include photoassociation (PA) [27], magnetoassociation (MA) [28] and magnetic Feshbach-optimized photoassociation (FOPA) * Author to whom any correspondence should be addressed.…”

Formation of ultracold ground-state CsYb molecules via Feshbach-optimized photoassociation

“…Alkaline-earth metal 84 Sr 2 molecules were produced by using Bose-enhanced PA and then transferred to the ground electronic state via the stimulated Raman adiabatic passage technique [40]. A twofrequency PA of 86 Sr atoms was investigated both theoretically and experimentally [41,42]. PA spectroscopy of 173 Yb atoms and the Zeeman effect were observed [43].…”