The effects of Feshbach resonance on spectral shifts in photoassociation of Cs atoms.

We study the effects of magnetic Feshbach resonance on the shifts in photoassociation (PA) spectra of ultracold Cs atoms. A series of atom loss spectra show a linear variation of the frequency shift with the PA laser intensity at different magnetic fields near the d-wave Feshbach resonance of optically trapped Cs atoms. The magnetic field-dependence of the slope of the shift on the PA laser intensity exhibits a dispersive change near the Feshbach resonance.

Bichromatic Photoassociation Spectroscopy for the Determination of Rotational Constants of Cs 0 u + Long-Range State below the 6S + 6P Asymptote.

This article demonstrates new observation of the high-resolution ro-vibrational bichromatic photoassociation spectra (BPAS) of Cs in the 0u+ long-range state below the asymptotes 6S + 6P. By combining with a modulation spectroscopic technique, precise references of the frequency differences have been engineered through the BPAS, with which the rotational constants of low-lying vibrational levels of the Cs0u+ long-range state have been accurately determined by fitting the frequency differences to the non-rigid-rotor model. The rotational constants for the newly observed seven ro-vibrational levels are summarized and disagreement for the level ῦ = 498 is clarified.

Hyperfine structure of the NaCs bΠ state near the dissociation limit 3S + 6P observed with ultracold atomic photoassociation.

We report new observations of the hyperfine structure in three ro-vibrational levels of the bΠ state of NaCs near the dissociation limit 3S + 6P. The experiment was done via photoassociation of ultracold atoms in a dual-species dark-spot magneto-optical trap, and the spectra were measured as atomic trap losses. The simulation of the hyperfine structure showed that the greater part of the observed structure belongs to almost isolated levels of the bΠ state, but there are other parts of mixed character where the contribution from the Σ symmetry dominates.

The Rb 3Π state: Observation and analysis.

This paper reports observations and analysis of the Rb 3Π state. A total of 323 rovibrational term values spanning the range of the rotational quantum number = 7 through 77 and the vibrational quantum number = 2 through 23 (about 1/3 of the potential well depth) were measured using the optical-optical double resonance technique. The term values are simulated within a model of a piece-wise multi-parameter potential energy function based on the generalized splines.

Observation of photoassociation of ultracold sodium and cesium at the asymptote Na (3S) + Cs (6P).

We report on the production of ultracold heteronuclear NaCs* molecules in a dual-species magneto-optical trap through photoassociation. The electronically excited molecules are formed below the Na (3S) + Cs (6P) dissociation limit. 12 resonance lines are detected using trap-loss spectroscopy based on a highly sensitive modulation technique.

Manipulation of photoassociation of ultracold Cs atoms with tunable scattering length by external magnetic fields.

We demonstrate that for ultracold, optically trapped Cs atoms the photoassociation (PA) can be manipulated by using external uniform magnetic fields due to the alteration of the scattering wavefunction in the region of the free-bound optical transition. We present PA-induced atom loss measurements with the same intensity for PA laser but different external magnetic fields, and analyze main contributions of the PA to the variation of the number of atoms in the trap. The PA rate exhibits a strong dependence on the changing uniform magnetic field.

Re-examination of the Cs ground singlet XΣ and triplet aΣ states.

This paper clarifies the disagreement in the depth of the potential energy curve of the cesium dimer singlet ground state which has lasted for nearly a decade. We point out that the origin of this disagreement must be a technical misprint in the values of the three binding energies reported by Danzl et al. [Science 321, 1062 (2008)], while the XΣ state potential reported by Coxon and Hajigeorgiou [J.

Observations and analysis with the spline-based Rydberg-Klein-Rees approach for the 3(1)Σg(+) state of Rb2.

Ro-vibrational term values of the 3(1)Σg (+) state of (85,85)Rb2 and (85,87)Rb2 and resolved fluorescence spectra to the A(1)Σu (+) state are recorded following optical-optical double resonance excitation. The experimental data are heavily perturbed, and as a result, the standard analysis based on Dunham series representation of the energy levels fails. The analysis is done via modeling the adiabatic potential function with the Rydberg-Klein-Rees potential constructed from the generalized smoothing spline interpolation of the vibrational energies Gv and rotational constants Bv.

Observation and deperturbation of near-dissociation ro-vibrational structure of the Cs2 state 0u(+) (A(1)Σu(+)∼b(3)Π0+u) at the asymptote 6S1/2 + 6P1/2.

New ro-vibrational structures of cold Cs2 in the 0u(+) state near the asymptote 6S1/2 + 6P1/2 are resolved. The variation of the rotational constants shows that the related energy spectra are strongly perturbed. An analysis of new data along with the empirical and theoretical information available from other sources is performed.

New observation and combined analysis of the Cs2 0g(-), 0u(+), and 1g states at the asymptotes 6S1/2 + 6P1/2 and 6S1/2 + 6P3/2.

We report on new observations of the photoassociation spectroscopy of ultracold cesium molecules using a highly sensitive detection technique and a combined analysis with all observed electronic states. The technique is achieved by directly modulating the frequency of the trapping lasers of a magneto-optical trap. New observations of the Cs2 0g(-), 0u(+), and 1g states at the asymptotes 6S1/2 + 6P1/2 and 6S1/2 + 6P3/2 are reported.

Observation and calculation of the Cs2 2 3Delta(1g) and b 3Pi(0u) states.

The Cs(2) 2 (3)Delta(1g) and b (3)Pi(0u) states have been observed by infrared-infrared double resonance spectroscopy for the first time. 221 2 (3)Delta(1g)<--A (1)Sigma(u) (+)<--X (1)Sigma(g) (+) double resonance lines have been assigned to transitions into the 2 (3)Delta(1g) v=6-13 vibrational levels. Resolved fluorescence into the b (3)Pi(0u) v(')=0-48 levels has been recorded.

The 39K(2) 2(3)Sigma(g)+ state: observation and analysis.

The (39)K(2) 2 (3)Sigma(g) (+) state has been observed by perturbation-facilitated infrared-infrared double resonance spectroscopy and two-photon excitation. Resolved fluorescence spectra into the a (3)Sigma(u) (+) state have been recorded. The observed vibrational levels have been assigned as the v=23-25, 27, 28, 31-33, 38-45, 47, and 53 levels by comparing the observed and calculated spectra of the 2 (3)Sigma(g) (+)-->a (3)Sigma(u) (+) transitions.