arXiv:physics/0211098 · Physical Review A

Saturation in heteronuclear photoassociation of 6Li7Li

U. Schlöder, C. Silber, T. Deuschle, Claus Zimmermann

Published Dec 31, 2002• 42 citations

Abstract

We report heteronuclear photoassociation spectroscopy in a mixture of magneto-optically trapped ${}^{6}\mathrm{Li}$ and ${}^{7}\mathrm{Li}.$ The laser-induced decrease in the ${}^{7}\mathrm{Li}$ steady-state particle number, only appearing in the presence of ${}^{6}\mathrm{Li},$ gives clear evidence of photoassociation to form ${}^{6}{\mathrm{Li}}^{7}\mathrm{Li}.$ Hyperfine resolved spectra of the vibrational level $v=83$ of the singlet state ${\mathrm{A}}^{1}{\ensuremath{\Sigma}}_{u}^{+}$ have been taken up to intensities of $1000{\mathrm{W}/\mathrm{c}\mathrm{m}}^{2}.$ The absolute resonance frequencies and the rotational constant have been measured. Saturation of the photoassociation rate has been observed for two hyperfine transitions, which can be shown to be due to saturation of the rate coefficient near the unitarity limit. Saturation intensities on the order of $40{\mathrm{W}/\mathrm{c}\mathrm{m}}^{2}$ can be determined.

DOI: 10.1103/physreva.66.061403

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Photoassociation of ultracold LiRb * molecules: Observation of high efficiency and unitarity-limited rate saturation

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arXiv:1311.6297Physical Review AFeb 19, 201439 citations

Saturation of Photoassociation in Cs Magneto-optical Trap

Jie Ma, Wang Li-Rong, Ji Wei-Bang +2 more

Chinese Physics LettersJun 28, 200710 citations

Hyperfine structure in photoassociative spectra of Li26 and Li27

E. R. I. Abraham, W. I. McAlexander, Henk T. C. Stoof +1 more

Physical Review AMay 1, 199627 citations

Photoassociative Spectroscopy of Collisions Between Ultracold Lithium Atoms

E. Abraham

Jan 1, 19960 citations

Autler-Townes splitting in two-color photoassociation of 6Li

U. Schlöder, T. Deuschle, C. Silber +1 more

arXiv:physics/0309067Physical Review ANov 26, 200332 citations

Photoassociative creation of ultracold heteronuclear 6 Li 40 K * molecules

A. Ridinger, Saptarishi Chaudhuri, Thomas Salez +5 more

arXiv:1108.0618Europhysics Letters (EPL)Oct 14, 201137 citations

arXiv:physics/0211098 · Physical Review A

Saturation in heteronuclear photoassociation of 6Li7Li

U. Schlöder, C. Silber, T. Deuschle, Claus Zimmermann

Published Dec 31, 2002• 42 citations

arXiv HTML PDF

Abstract

We report heteronuclear photoassociation spectroscopy in a mixture of magneto-optically trapped

{}^{6}\mathrm{Li}

and

{}^{7}\mathrm{Li}.

The laser-induced decrease in the

{}^{7}\mathrm{Li}

steady-state particle number, only appearing in the presence of

{}^{6}\mathrm{Li},

gives clear evidence of photoassociation to form

{}^{6}{\mathrm{Li}}^{7}\mathrm{Li}.

Hyperfine resolved spectra of the vibrational level

v=83

of the singlet state

{\mathrm{A}}^{1}{\ensuremath{\Sigma}}_{u}^{+}

have been taken up to intensities of

1000{\mathrm{W}/\mathrm{c}\mathrm{m}}^{2}.

The absolute resonance frequencies and the rotational constant have been measured. Saturation of the photoassociation rate has been observed for two hyperfine transitions, which can be shown to be due to saturation of the rate coefficient near the unitarity limit. Saturation intensities on the order of

40{\mathrm{W}/\mathrm{c}\mathrm{m}}^{2}

can be determined.

DOI: 10.1103/physreva.66.061403

Related papers

Photoassociation of ultracold LiRb * molecules: Observation of high efficiency and unitarity-limited rate saturation

Sourav Dutta, John Lorenz, Adeel Altaf +2 more

We report the production of ultracold heteronuclear $^{7}\mathrm{Li}^{85}\mathrm{Rb}$ molecules in excited electronic states by photoassociation (PA) of ultracold $^{7}\mathrm{Li}$ and $^{85}\mathrm{Rb}$ atoms. PA is performed in a dual-species $^{7}\mathrm{Li}$ - $^{85}\mathrm{Rb}$ magneto-optical trap (MOT) and the PA resonances are detected using trap loss spectroscopy. We identify several strong PA resonances below the Li (2 $s$ ${}^{2}$ ${S}_{1/2}$ ) + Rb (5 $p$ ${}^{2}{P}_{3/2}$ ) asymptote and experimentally determine the long range ${C}_{6}$ dispersion coefficients. We find a molecule formation rate ( ${P}_{\mathrm{LiRb}}$ ) of 3.5 \ifmmode\times\else\texttimes\fi{} 10 ${}^{7}$ s${}^{\ensuremath{-}1}$ and a PA rate coefficient ( ${K}_{\mathrm{PA}}$ ) of 1.3 \ifmmode\times\else\texttimes\fi{} 10${}^{\ensuremath{-}10}$ cm ${}^{3}$ /s, the highest among heteronuclear bi-alkali-metal molecules. At large PA laser intensity we observe the saturation of the PA rate coefficient ( ${K}_{\mathrm{PA}}$ ) close to the theoretical value at the unitarity limit.We report the production of ultracold heteronuclear $^{7}\mathrm{Li}^{85}\mathrm{Rb}$ molecules in excited electronic states by photoassociation (PA) of ultracold $^{7}\mathrm{Li}$ and $^{85}\mathrm{Rb}$ atoms. PA is performed in a dual-species $^{7}\mathrm{Li}$-$^{85}\mathrm{Rb}$ magneto-optical trap (MOT) and the PA resonances are detected using trap loss spectroscopy. We identify several strong PA resonances below the Li (2$s$ ${}^{2}$${S}_{1/2}$) + Rb (5$p$ ${}^{2}{P}_{3/2}$) asymptote and experimentally determine the long range ${C}_{6}$ dispersion coefficients. We find a molecule formation rate (${P}_{\mathrm{LiRb}}$) of 3.5 \ifmmode\times\else\texttimes\fi{} 10${}^{7}$ s${}^{\ensuremath{-}1}$ and a PA rate coefficient (${K}_{\mathrm{PA}}$) of 1.3 \ifmmode\times\else\texttimes\fi{} 10${}^{\ensuremath{-}10}$ cm${}^{3}$/s, the highest among heteronuclear bi-alkali-metal molecules. At large PA laser intensity we observe the saturation of the PA rate coefficient (${K}_{\mathrm{PA}}$) close to the theoretical value at the unitarity limit.

arXiv:1311.6297Physical Review AFeb 19, 201439 citations

Saturation of Photoassociation in Cs Magneto-optical Trap

Jie Ma, Wang Li-Rong, Ji Wei-Bang +2 more

An ultrahigh resolution photoassociation spectrum of caesium atoms in a magneto-optical trap is presented. Hyperfine structure of the excited state molecule is obtained by using the lock-in method based on modulated cold atoms in this spectrum. Amplitude of resonant lines related to the rotational levels increases with photoassociation laser intensity, and saturation effect of photoassociation of cold atoms is observed in our experiment. The saturation intensity of photoassociation is deduced by fitting the experimental data to a saturation model based on scattering theory. Differences among saturation intensities of different rotational progressions in the ν = 55 vibrational state of the caesium molecular long-range 0 g − state have been found.An ultrahigh resolution photoassociation spectrum of caesium atoms in a magneto-optical trap is presented. Hyperfine structure of the excited state molecule is obtained by using the lock-in method based on modulated cold atoms in this spectrum. Amplitude of resonant lines related to the rotational levels increases with photoassociation laser intensity, and saturation effect of photoassociation of cold atoms is observed in our experiment. The saturation intensity of photoassociation is deduced by fitting the experimental data to a saturation model based on scattering theory. Differences among saturation intensities of different rotational progressions in the ν = 55 vibrational state of the caesium molecular long-range 0 g − state have been found.

Chinese Physics LettersJun 28, 200710 citations

Hyperfine structure in photoassociative spectra of Li26 and Li27

E. R. I. Abraham, W. I. McAlexander, Henk T. C. Stoof +1 more

We present spectra of hyperfine resolved vibrational levels of the ${\mathit{A}}^{1}$ ${\mathrm{\ensuremath{\Sigma}}}_{\mathit{u}}^{+}$and 1 ${\mathrm{}}^{3}$ ${\mathrm{\ensuremath{\Sigma}}}_{\mathit{g}}^{+}$ states of $^{6}\mathrm{Li}_{2}$ and $^{7}\mathrm{Li}_{2}$ obtained via photoassociation of colliding ultracold atoms in a magneto-optical trap. A simple first-order perturbation theory analysis accurately accounts for the frequency splittings and relative transition strengths of all observed hyperfine features. Assignment of the hyperfine structure allows accurate determination of a vibrational level center of gravity, which significantly decreases the experimental uncertainty of vibrational energies. Differences in the spectra of $^{6}\mathrm{Li}_{2}$ and $^{7}\mathrm{Li}_{2}$ are attributed to quantum statistics. The 1 ${\mathrm{}}^{3}$ ${\mathrm{\ensuremath{\Sigma}}}_{\mathit{g}}^{+}$ series obeys Hund's case ${\mathit{b}}_{\mathrm{\ensuremath{\beta}}\mathit{S}}$ coupling and the hyperfine constant is extracted for both isotopes. \textcopyright{} 1996 The American Physical Society.We present spectra of hyperfine resolved vibrational levels of the ${\mathit{A}}^{1}$${\mathrm{\ensuremath{\Sigma}}}_{\mathit{u}}^{+}$and 1${\mathrm{}}^{3}$${\mathrm{\ensuremath{\Sigma}}}_{\mathit{g}}^{+}$ states of $^{6}\mathrm{Li}_{2}$ and $^{7}\mathrm{Li}_{2}$ obtained via photoassociation of colliding ultracold atoms in a magneto-optical trap. A simple first-order perturbation theory analysis accurately accounts for the frequency splittings and relative transition strengths of all observed hyperfine features. Assignment of the hyperfine structure allows accurate determination of a vibrational level center of gravity, which significantly decreases the experimental uncertainty of vibrational energies. Differences in the spectra of $^{6}\mathrm{Li}_{2}$ and $^{7}\mathrm{Li}_{2}$ are attributed to quantum statistics. The 1${\mathrm{}}^{3}$${\mathrm{\ensuremath{\Sigma}}}_{\mathit{g}}^{+}$ series obeys Hund's case ${\mathit{b}}_{\mathrm{\ensuremath{\beta}}\mathit{S}}$ coupling and the hyperfine constant is extracted for both isotopes. \textcopyright{} 1996 The American Physical Society.

Physical Review AMay 1, 199627 citations

Photoassociative Spectroscopy of Collisions Between Ultracold Lithium Atoms

E. Abraham

The spectra of the high-lying vibrational levels of the $A\\sp1\\Sigma\\sbsp{u}{+}$ and $1\\sp3\\Sigma\\sbsp{g}{+}$ singly excited states of both $\\sp6\\rm Li\\sb2$ and $\\sp7\\rm Li\\sb2$ are obtained via photoassociation of colliding ultracold atoms confined in a magneto-optical trap. The least bound state of the $a\\sp3\\Sigma\\sbsp{u}{+}$ ground state potential, obtained by two-photon photoassociative spectroscopy, is also presented for both $\\sp7\\rm Li\\sb2$ and $\\sp6\\rm Li\\sb2$ . The vibrational levels have resolved hyperfine structure, whose relative energy splittings and transition strengths are accurately modeled. The photoassociative spectra are used to precisely determine both the singlet and triplet s-wave scattering lengths for both isotopes, which are important parameters in systems designed to observe quantum degenerate effects and Bose-Einstein condensation.The spectra of the high-lying vibrational levels of the $A\\sp1\\Sigma\\sbsp{u}{+}$ and $1\\sp3\\Sigma\\sbsp{g}{+}$ singly excited states of both $\\sp6\\rm Li\\sb2$ and $\\sp7\\rm Li\\sb2$ are obtained via photoassociation of colliding ultracold atoms confined in a magneto-optical trap. The least bound state of the $a\\sp3\\Sigma\\sbsp{u}{+}$ ground state potential, obtained by two-photon photoassociative spectroscopy, is also presented for both $\\sp7\\rm Li\\sb2$ and $\\sp6\\rm Li\\sb2$. The vibrational levels have resolved hyperfine structure, whose relative energy splittings and transition strengths are accurately modeled. The photoassociative spectra are used to precisely determine both the singlet and triplet s-wave scattering lengths for both isotopes, which are important parameters in systems designed to observe quantum degenerate effects and Bose-Einstein condensation.

Jan 1, 19960 citations

Autler-Townes splitting in two-color photoassociation of 6Li

U. Schlöder, T. Deuschle, C. Silber +1 more

We report on high-resolution two-color photoassociation spectroscopy in the triplet system of magneto-optically trapped ${}^{6}\mathrm{Li}.$ Photoassociation is induced from the ground-state asymptote to the $v=59$ level of the excited $1{}^{3}{\ensuremath{\Sigma}}_{g}^{+}$ state. This level is coupled to the $v=9$ level of the triplet ground state $a{}^{3}{\ensuremath{\Sigma}}_{u}^{+}$ by the light field of a Raman laser. The absolute transition frequencies are measured with an iodine frequency standard and the binding energy of the ground state is determined to be $24.391\ifmmode\pm\else\textpm\fi{}0.020\mathrm{GHz}.$ Strong coupling of the bound molecular states has been observed as Autler-Townes splitting in the photoassociation signal for different detunings of the Raman laser. From the splitting we determine the spontaneous bound-bound decay rate to be $4.3\ifmmode\times\else\texttimes\fi{}{10}^{5}{\mathrm{s}}^{\ensuremath{-}1}$ and estimate the molecule formation rate. The observed line shapes are in good agreement with the theoretical model.We report on high-resolution two-color photoassociation spectroscopy in the triplet system of magneto-optically trapped ${}^{6}\mathrm{Li}.$ Photoassociation is induced from the ground-state asymptote to the $v=59$ level of the excited $1{}^{3}{\ensuremath{\Sigma}}_{g}^{+}$ state. This level is coupled to the $v=9$ level of the triplet ground state $a{}^{3}{\ensuremath{\Sigma}}_{u}^{+}$ by the light field of a Raman laser. The absolute transition frequencies are measured with an iodine frequency standard and the binding energy of the ground state is determined to be $24.391\ifmmode\pm\else\textpm\fi{}0.020\mathrm{GHz}.$ Strong coupling of the bound molecular states has been observed as Autler-Townes splitting in the photoassociation signal for different detunings of the Raman laser. From the splitting we determine the spontaneous bound-bound decay rate to be $4.3\ifmmode\times\else\texttimes\fi{}{10}^{5}{\mathrm{s}}^{\ensuremath{-}1}$ and estimate the molecule formation rate. The observed line shapes are in good agreement with the theoretical model.

arXiv:physics/0309067Physical Review ANov 26, 200332 citations

Photoassociative creation of ultracold heteronuclear 6 Li 40 K * molecules

A. Ridinger, Saptarishi Chaudhuri, Thomas Salez +5 more

We investigate the formation of weakly bound, electronically excited, heteronuclear 6 Li 40 K * molecules by single-photon photoassociation in a magneto-optical trap. We performed trap loss spectroscopy within a range of 325 GHz below the Li(2 S 1/2 )+K(4 P 3/2 ) and Li(2 S 1/2 )+K(4 P 1/2 ) asymptotic states and observed more than 60 resonances, which we identify as rovibrational levels of 7 of 8 attractive long-range molecular potentials. The long-range dispersion coefficients and rotational constants are derived. We find large molecule formation rates of up to ∼3.5 × 10 7 s − 1 , which are shown to be comparable to those for homonuclear 40 K 2 * . Using a theoretical model we infer decay rates to the deeply bound electronic ground-state vibrational level X 1 Σ + ( v '=3) of ∼5 × 10 4 s −1 . Our results pave the way for the production of ultracold bosonic ground-state 6 Li 40 K molecules which exhibit a large intrinsic permanent electric dipole moment.We investigate the formation of weakly bound, electronically excited, heteronuclear 6 Li 40 K * molecules by single-photon photoassociation in a magneto-optical trap. We performed trap loss spectroscopy within a range of 325 GHz below the Li(2 S 1/2 )+K(4 P 3/2 ) and Li(2 S 1/2 )+K(4 P 1/2 ) asymptotic states and observed more than 60 resonances, which we identify as rovibrational levels of 7 of 8 attractive long-range molecular potentials. The long-range dispersion coefficients and rotational constants are derived. We find large molecule formation rates of up to ∼3.5 × 10 7 s − 1 , which are shown to be comparable to those for homonuclear 40 K 2 * . Using a theoretical model we infer decay rates to the deeply bound electronic ground-state vibrational level X 1 Σ + ( v '=3) of ∼5 × 10 4 s −1 . Our results pave the way for the production of ultracold bosonic ground-state 6 Li 40 K molecules which exhibit a large intrinsic permanent electric dipole moment.

arXiv:1108.0618Europhysics Letters (EPL)Oct 14, 201137 citations

We report heteronuclear photoassociation spectroscopy in a mixture of magneto-optically trapped

{}^{6}\mathrm{Li}

and

{}^{7}\mathrm{Li}.

The laser-induced decrease in the

{}^{7}\mathrm{Li}

steady-state particle number, only appearing in the presence of

{}^{6}\mathrm{Li},

gives clear evidence of photoassociation to form

{}^{6}{\mathrm{Li}}^{7}\mathrm{Li}.

Hyperfine resolved spectra of the vibrational level

v=83

of the singlet state

{\mathrm{A}}^{1}{\ensuremath{\Sigma}}_{u}^{+}

have been taken up to intensities of

1000{\mathrm{W}/\mathrm{c}\mathrm{m}}^{2}.

40{\mathrm{W}/\mathrm{c}\mathrm{m}}^{2}

can be determined.

We report the production of ultracold heteronuclear

^{7}\mathrm{Li}^{85}\mathrm{Rb}

molecules in excited electronic states by photoassociation (PA) of ultracold

^{7}\mathrm{Li}

and

^{85}\mathrm{Rb}

atoms. PA is performed in a dual-species

^{7}\mathrm{Li}

^{85}\mathrm{Rb}

magneto-optical trap (MOT) and the PA resonances are detected using trap loss spectroscopy. We identify several strong PA resonances below the Li (2

s

{}^{2}

{S}_{1/2}

) + Rb (5

p

{}^{2}{P}_{3/2}

) asymptote and experimentally determine the long range

{C}_{6}

dispersion coefficients. We find a molecule formation rate (

{P}_{\mathrm{LiRb}}

) of 3.5 \ifmmode\times\else\texttimes\fi{} 10

{}^{7}

s${}^{\ensuremath{-}1}$ and a PA rate coefficient (

{K}_{\mathrm{PA}}

) of 1.3 \ifmmode\times\else\texttimes\fi{} 10${}^{\ensuremath{-}10}$ cm

{}^{3}

/s, the highest among heteronuclear bi-alkali-metal molecules. At large PA laser intensity we observe the saturation of the PA rate coefficient (

{K}_{\mathrm{PA}}

) close to the theoretical value at the unitarity limit.

We present spectra of hyperfine resolved vibrational levels of the

{\mathit{A}}^{1}

${\mathrm{\ensuremath{\Sigma}}}_{\mathit{u}}^{+}$and 1

{\mathrm{}}^{3}

${\mathrm{\ensuremath{\Sigma}}}_{\mathit{g}}^{+}$ states of

^{6}\mathrm{Li}_{2}

and

^{7}\mathrm{Li}_{2}

obtained via photoassociation of colliding ultracold atoms in a magneto-optical trap. A simple first-order perturbation theory analysis accurately accounts for the frequency splittings and relative transition strengths of all observed hyperfine features. Assignment of the hyperfine structure allows accurate determination of a vibrational level center of gravity, which significantly decreases the experimental uncertainty of vibrational energies. Differences in the spectra of

^{6}\mathrm{Li}_{2}

and

^{7}\mathrm{Li}_{2}

are attributed to quantum statistics. The 1

{\mathrm{}}^{3}

${\mathrm{\ensuremath{\Sigma}}}_{\mathit{g}}^{+}$ series obeys Hund's case ${\mathit{b}}_{\mathrm{\ensuremath{\beta}}\mathit{S}}$ coupling and the hyperfine constant is extracted for both isotopes. \textcopyright{} 1996 The American Physical Society.

The spectra of the high-lying vibrational levels of the

A\\sp1\\Sigma\\sbsp{u}{+}

and

1\\sp3\\Sigma\\sbsp{g}{+}

singly excited states of both

\\sp6\\rm Li\\sb2

and

\\sp7\\rm Li\\sb2

are obtained via photoassociation of colliding ultracold atoms confined in a magneto-optical trap. The least bound state of the

a\\sp3\\Sigma\\sbsp{u}{+}

ground state potential, obtained by two-photon photoassociative spectroscopy, is also presented for both

\\sp7\\rm Li\\sb2

and

\\sp6\\rm Li\\sb2

. The vibrational levels have resolved hyperfine structure, whose relative energy splittings and transition strengths are accurately modeled. The photoassociative spectra are used to precisely determine both the singlet and triplet s-wave scattering lengths for both isotopes, which are important parameters in systems designed to observe quantum degenerate effects and Bose-Einstein condensation.

We report on high-resolution two-color photoassociation spectroscopy in the triplet system of magneto-optically trapped

{}^{6}\mathrm{Li}.

Photoassociation is induced from the ground-state asymptote to the

v=59

level of the excited $1{}^{3}{\ensuremath{\Sigma}}_{g}^{+}$ state. This level is coupled to the

v=9

level of the triplet ground state $a{}^{3}{\ensuremath{\Sigma}}_{u}^{+}$ by the light field of a Raman laser. The absolute transition frequencies are measured with an iodine frequency standard and the binding energy of the ground state is determined to be $24.391\ifmmode\pm\else\textpm\fi{}0.020\mathrm{GHz}.$ Strong coupling of the bound molecular states has been observed as Autler-Townes splitting in the photoassociation signal for different detunings of the Raman laser. From the splitting we determine the spontaneous bound-bound decay rate to be $4.3\ifmmode\times\else\texttimes\fi{}{10}^{5}{\mathrm{s}}^{\ensuremath{-}1}$ and estimate the molecule formation rate. The observed line shapes are in good agreement with the theoretical model.