Two-color photoassociation spectroscopy of the lowest triplet potential of Na2

Abstract

Photoassociation of ultracold K atoms: Observation of high lying levels of the 1 g 1 1 Π g molecular state of K 2 J. Chem. Phys. 118, 7837 (2003); 10.1063/1.1563609Long-range interaction of the 39K(4s)+ 39K(4p) asymptote by photoassociative spectroscopy. I. The 0 g − pure long-range state and the long-range potential constantsWe have performed a type of Autler-Townes spectroscopy to locate a number of rovibrational-hyperfine levels of the a 3 ⌺ u ϩ potential, the lowest triplet potential of the Na 2 dimer. The spectroscopy starts with the photoassociation of ultracold atoms in a magneto-optical trap. We have measured the binding energies of over 100 individual states spanning the vibrational levels vϭ8 -15 of this potential ͑binding energies up to 27 cm Ϫ1 ). We obtain a typical accuracy of 15 MHz and a typical resolution of 20 MHz, improving on the 10 GHz accuracy and 30 GHz resolution previously available for the vibrational states vϽ12. Vibrational, rotational, and hyperfine structures are resolved. Additionally, we have been able to resolve the magnetic electron-electron spin-spin dipole splitting of a number of these hyperfine levels. The measured rotational and hyperfine structures show good agreement with theoretical calculations. An analysis of the remaining discrepancies indicates where possible refinements to the potentials can be made. We also observe evidence for the presence of second-order spin-orbit coupling.

Feshbach spectroscopy and analysis of the interaction potentials of ultracold sodium

“…For sodium this ansatz was first used in Ref. [12], where they found that a non-negligible a SO is needed to describe the photoassociation data. We represent the X 1 + g and a 3 + u Born-Oppenheimer potentials using a separate functional form for three regions of the internuclear separation: a short-range repulsive wall for R < R inn , an asymptotic long-range region for R > R out , and an intermediate deeply bound region in between.…”

“…(2) with R-dependent interaction potentials and coupling terms. The R-dependent functions are found in a fit to all known Feshbach resonances and existing spectroscopic data of more deeply bound rovibrational levels of the X 1 + g and a 3 + u potentials [8][9][10][11][12]. Data from conventional spectroscopy by Kush and Hessel [39] and by Barrow et al [40] for the ground-state X 1 + g potential and by Li Li et al [41] for the lowest triplet state a 3 + u potential are also included.…”

“…In addition, Refs. [11,12] presented an extensive study of the lowest triplet potential a 3 + u by two-color photoassociation spectroscopy on magneto-optically trapped Na atoms. However, more and sufficiently cold atomic sample, on which an external homogeneous magnetic field can be applied.…”

Saturation ofCs2photoassociation in an optical dipole trap

“…In contrast to this, the successful formation of ultacold molecular ensembles in the absolute rovibrational ground state, which is important if one wants to study molecular collisions and reactions over long interaction times, is still at large. Future routes for the production of absolute ground state molecules from a pair of atoms will certainly involve Raman type coupling schemes [12,13,14]. A very interesting approach to transfer highly vibrationally excited molecules into the vibrational ground state proposes the application of optimally controlled femtosecond laser pulses [15].…”

Two-photon photoassociation spectroscopy of an ultracold heteronuclear molecule

“…On the other hand, an all optical scheme such as the Raman-type two-photon PA [24] of ultracold atoms is in principle applicable to all species and is capable of producing ultracold molecules in deeply bound states. The scheme has been previously implemented on homonuclear molecules [25][26][27][28][29][30][31][32][33] but has never been reported to be observed in heteronuclear bi-alkali molecules.…”