Photoassociation Spectroscopy of the Lowest Triplet Potential of Na2

We have performed a type of Autler–Townes spectroscopy to locate a number of rovibrational-hyperfine levels of the a 3Σu+ potential, the lowest triplet potential of the Na2 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 v=8–15 of this potential (binding energies up to 27 cm−1). 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 v<12. 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.We have performed a type of Autler–Townes spectroscopy to locate a number of rovibrational-hyperfine levels of the a 3Σu+ potential, the lowest triplet potential of the Na2 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 v=8–15 of this potential (binding energies up to 27 cm−1). 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 v<12. 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.

The Journal of Chemical PhysicsJul 17, 200318 citations

Ground-state scattering lengths for potassium isotopes determined by double-resonance photoassociative spectroscopy of ultracold 39K

Haijin Wang, Anguel Nikolov, J. R. Ensher +9 more

We use double-resonance photoassociative spectroscopy of ultracold ${}^{39}\mathrm{K}$ atoms to precisely determine the triplet $a{}^{3}{\ensuremath{\Sigma}}_{u}^{+}$ scattering length for the various isotopes of potassium. Photoassociation of free ${}^{39}\mathrm{K}$ atoms to the pure long-range ${0}_{g}^{\ensuremath{-}}{(v}^{\ensuremath{'}}=0,{J}^{\ensuremath{'}}=2)$ level is followed by stimulated emission to high-lying levels of the $a{}^{3}{\ensuremath{\Sigma}}_{u}^{+}$ potential. The binding energies of levels within 5 GHz below the lowest ground-state ${4s}_{1/2}{(f}_{a}{=1)+4s}_{1/2}{(f}_{b}=1)$ hyperfine asymptote are measured by both trap loss and ionization detection. The locations of these near-threshold hyperfine-coupled molecular levels allow us to constrain the triplet potential and thereby determine the triplet scattering length. The result for ${}^{39}\mathrm{K},$ ${a}_{t}=\ensuremath{-}33\ifmmode\pm\else\textpm\fi{}{5a}_{0}$ ${(1a}_{0}=0.0529177 \mathrm{nm}),$ is a factor of $\ensuremath{\sim}5$ improvement over previous determinations and establishes that a large ${}^{39}\mathrm{K}$ Bose-Einstein condensate will not be stable.We use double-resonance photoassociative spectroscopy of ultracold ${}^{39}\mathrm{K}$ atoms to precisely determine the triplet $a{}^{3}{\ensuremath{\Sigma}}_{u}^{+}$ scattering length for the various isotopes of potassium. Photoassociation of free ${}^{39}\mathrm{K}$ atoms to the pure long-range ${0}_{g}^{\ensuremath{-}}{(v}^{\ensuremath{'}}=0,{J}^{\ensuremath{'}}=2)$ level is followed by stimulated emission to high-lying levels of the $a{}^{3}{\ensuremath{\Sigma}}_{u}^{+}$ potential. The binding energies of levels within 5 GHz below the lowest ground-state ${4s}_{1/2}{(f}_{a}{=1)+4s}_{1/2}{(f}_{b}=1)$ hyperfine asymptote are measured by both trap loss and ionization detection. The locations of these near-threshold hyperfine-coupled molecular levels allow us to constrain the triplet potential and thereby determine the triplet scattering length. The result for ${}^{39}\mathrm{K},$ ${a}_{t}=\ensuremath{-}33\ifmmode\pm\else\textpm\fi{}{5a}_{0}$ ${(1a}_{0}=0.0529177 \mathrm{nm}),$ is a factor of $\ensuremath{\sim}5$ improvement over previous determinations and establishes that a large ${}^{39}\mathrm{K}$ Bose-Einstein condensate will not be stable.

Physical Review AOct 12, 200062 citations

Photoassociation Spectroscopy: Determination of Parameters of Potentials of Diatomic Molecules

James Gary Eden, Henry Tran, V. S. Zuev

Journal of Russian Laser ResearchMar 1, 19981 citation

Two-color Photoassociation Spectroscopy Of Ultracold Sodium

K. M. Jones, S. Maleki, L. P. Ratliff

Quantum Electronics and Laser Science ConferenceJan 1, 19971 citation

Spectroscopy of autoionizing doubly excited states in ultracold Na2 molecules produced by photoassociation

Arjen Amelink, K. M. Jones, Paul D. Lett +2 more

We have performed photoassociation spectroscopy to study the doubly excited states of ${\mathrm{Na}}_{2}$ involved in the associative ionization of colliding $\mathrm{Na}(3P)$ atoms. Rovibrational levels of two doubly excited potentials connected to the ${P}_{3/2}{+P}_{3/2}$ asymptote, one of ${0}_{u}^{\ensuremath{-}}$ and one of ${1}_{u}$ symmetry, have been identified. These two doubly excited potentials dominate the route to ionization used in photoassociation experiments of cold Na. Binding energies and rotational constants for all the vibrational levels with binding energies $<50\mathrm{GHz}$ have been measured. The asymptotic potentials and short-range ionization probabilities are extracted from the data.We have performed photoassociation spectroscopy to study the doubly excited states of ${\mathrm{Na}}_{2}$ involved in the associative ionization of colliding $\mathrm{Na}(3P)$ atoms. Rovibrational levels of two doubly excited potentials connected to the ${P}_{3/2}{+P}_{3/2}$ asymptote, one of ${0}_{u}^{\ensuremath{-}}$ and one of ${1}_{u}$ symmetry, have been identified. These two doubly excited potentials dominate the route to ionization used in photoassociation experiments of cold Na. Binding energies and rotational constants for all the vibrational levels with binding energies $<50\mathrm{GHz}$ have been measured. The asymptotic potentials and short-range ionization probabilities are extracted from the data.

Physical Review AMar 9, 200025 citations

We use double-resonance photoassociative spectroscopy of ultracold

{}^{39}\mathrm{K}

atoms to precisely determine the triplet $a{}^{3}{\ensuremath{\Sigma}}_{u}^{+}$ scattering length for the various isotopes of potassium. Photoassociation of free

{}^{39}\mathrm{K}

atoms to the pure long-range ${0}_{g}^{\ensuremath{-}}{(v}^{\ensuremath{'}}=0,{J}^{\ensuremath{'}}=2)$ level is followed by stimulated emission to high-lying levels of the $a{}^{3}{\ensuremath{\Sigma}}_{u}^{+}$ potential. The binding energies of levels within 5 GHz below the lowest ground-state

{4s}_{1/2}{(f}_{a}{=1)+4s}_{1/2}{(f}_{b}=1)

hyperfine asymptote are measured by both trap loss and ionization detection. The locations of these near-threshold hyperfine-coupled molecular levels allow us to constrain the triplet potential and thereby determine the triplet scattering length. The result for

{}^{39}\mathrm{K},

${a}_{t}=\ensuremath{-}33\ifmmode\pm\else\textpm\fi{}{5a}_{0}$

{(1a}_{0}=0.0529177 \mathrm{nm}),

is a factor of $\ensuremath{\sim}5$ improvement over previous determinations and establishes that a large

{}^{39}\mathrm{K}

Bose-Einstein condensate will not be stable.

We have performed photoassociation spectroscopy to study the doubly excited states of

{\mathrm{Na}}_{2}

involved in the associative ionization of colliding

\mathrm{Na}(3P)

atoms. Rovibrational levels of two doubly excited potentials connected to the

{P}_{3/2}{+P}_{3/2}

asymptote, one of ${0}_{u}^{\ensuremath{-}}$ and one of

{1}_{u}

symmetry, have been identified. These two doubly excited potentials dominate the route to ionization used in photoassociation experiments of cold Na. Binding energies and rotational constants for all the vibrational levels with binding energies

<50\mathrm{GHz}

have been measured. The asymptotic potentials and short-range ionization probabilities are extracted from the data.