We present a technique for empirically determining the photon scattering rate of atoms in a magneto-optical trap (MOT). An accurate measurement of the scattering rate provides a way to accurately determine the number of atoms in the MOT, the excited-state fraction, and the in situ light intensity experienced by the atoms in the trap. We validate this technique for determining the scattering rate by comparing the atom number determined by the fluorescence emitted by atoms in a MOT with an independent and unrelated measure of the number determined by an absorption measurement of an optical pumping beam. We also observe minor deviations from the two-level model for the single-photon scattering rate and extend our analysis to a four-level model. The main advantage of the method described here is that it provides a simple way of determining the photon scattering rate of the MOT empirically and, thus, of evaluating the atom number from fluorescence measurements more accurately.We present a technique for empirically determining the photon scattering rate of atoms in a magneto-optical trap (MOT). An accurate measurement of the scattering rate provides a way to accurately determine the number of atoms in the MOT, the excited-state fraction, and the in situ light intensity experienced by the atoms in the trap. We validate this technique for determining the scattering rate by comparing the atom number determined by the fluorescence emitted by atoms in a MOT with an independent and unrelated measure of the number determined by an absorption measurement of an optical pumping beam. We also observe minor deviations from the two-level model for the single-photon scattering rate and extend our analysis to a four-level model. The main advantage of the method described here is that it provides a simple way of determining the photon scattering rate of the MOT empirically and, thus, of evaluating the atom number from fluorescence measurements more accurately.

Physical Review ADec 2, 20139 citations

Topics in photon-atom scattering

Jonathan Carney

Jan 1, 19990 citations

Feshbach spectroscopy of a K−Rb atomic mixture

Francesca Ferlaino, Chiara D’Errico, G. Roati +4 more

We perform extensive magnetic Feshbach spectroscopy of an ultracold mixture of fermionic $^{40}\mathrm{K}$ and bosonic $^{87}\mathrm{Rb}$ atoms. The magnetic-field locations of 13 interspecies resonances are used to construct a quantum collision model able to predict accurate collisional parameters for all $\mathrm{K}\text{\ensuremath{-}}\mathrm{Rb}$ isotopic pairs. In particular, we determine the interspecies $s$ -wave singlet and triplet scattering lengths for the $^{40}\mathrm{K}\text{\ensuremath{-}}^{87}\mathrm{Rb}$ mixture as $(\ensuremath{-}108\ifmmode\pm\else\textpm\fi{}3){a}_{0}$ and $(\ensuremath{-}205\ifmmode\pm\else\textpm\fi{}5){a}_{0}$, respectively. We also predict accurate scattering lengths and the position of Feshbach resonances for the other $\mathrm{K}\text{\ensuremath{-}}\mathrm{Rb}$ isotopic pairs. We discuss the consequences of our results for current and future experiments with ultracold $\mathrm{K}\text{\ensuremath{-}}\mathrm{Rb}$ mixtures.We perform extensive magnetic Feshbach spectroscopy of an ultracold mixture of fermionic $^{40}\mathrm{K}$ and bosonic $^{87}\mathrm{Rb}$ atoms. The magnetic-field locations of 13 interspecies resonances are used to construct a quantum collision model able to predict accurate collisional parameters for all $\mathrm{K}\text{\ensuremath{-}}\mathrm{Rb}$ isotopic pairs. In particular, we determine the interspecies $s$-wave singlet and triplet scattering lengths for the $^{40}\mathrm{K}\text{\ensuremath{-}}^{87}\mathrm{Rb}$ mixture as $(\ensuremath{-}108\ifmmode\pm\else\textpm\fi{}3){a}_{0}$ and $(\ensuremath{-}205\ifmmode\pm\else\textpm\fi{}5){a}_{0}$, respectively. We also predict accurate scattering lengths and the position of Feshbach resonances for the other $\mathrm{K}\text{\ensuremath{-}}\mathrm{Rb}$ isotopic pairs. We discuss the consequences of our results for current and future experiments with ultracold $\mathrm{K}\text{\ensuremath{-}}\mathrm{Rb}$ mixtures.

arXiv:cond-mat/0510630Physical Review AApr 14, 2006161 citations

Scattering of Photons by Atomic Systems

K. T. Hecht

Graduate texts in contemporary physicsJan 1, 20000 citations

Spotlight on Photon-Photon Scattering

Anonymous

PhysicsAug 22, 20131 citation

Elastic scattering of hydrogen atoms at low temperatures

Michael J. Jamieson, A. Dalgarno, John N. Yukich

The elastic scattering of two hydrogen atoms interacting at very small energies is explored numerically using the most accurate potential-energy curves available for the X $^{1}\mathrm{\ensuremath{\Sigma}}_{\mathrm{g}}^{+}$ and $^{3}\mathrm{\ensuremath{\Sigma}}_{\mathrm{u}}^{+}$ states of ${\mathrm{H}}_{2}$ . The scattering lengths and low-temperature-averaged cross sections are determined and compared with previous calculations. The scattering lengths are 0.41 ${\mathit{a}}_{0}$ for the singlet case and 1.91 ${\mathit{a}}_{0}$ for the triplet. The predicted total triplet cross section at 2 K is 5.5\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}15}$ ${\mathrm{cm}}^{2}$ but it could be lower, at 4.8\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}15}$ ${\mathrm{cm}}^{2}$ , with a different fit to the triplet potential between 12 ${\mathit{a}}_{0}$ and 15 ${\mathit{a}}_{0}$ . A more accurate triplet-state potential is needed at these separations.The elastic scattering of two hydrogen atoms interacting at very small energies is explored numerically using the most accurate potential-energy curves available for the X $^{1}\mathrm{\ensuremath{\Sigma}}_{\mathrm{g}}^{+}$ and $^{3}\mathrm{\ensuremath{\Sigma}}_{\mathrm{u}}^{+}$ states of ${\mathrm{H}}_{2}$. The scattering lengths and low-temperature-averaged cross sections are determined and compared with previous calculations. The scattering lengths are 0.41${\mathit{a}}_{0}$ for the singlet case and 1.91${\mathit{a}}_{0}$ for the triplet. The predicted total triplet cross section at 2 K is 5.5\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}15}$ ${\mathrm{cm}}^{2}$ but it could be lower, at 4.8\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}15}$ ${\mathrm{cm}}^{2}$, with a different fit to the triplet potential between 12${\mathit{a}}_{0}$ and 15${\mathit{a}}_{0}$. A more accurate triplet-state potential is needed at these separations.

Physical Review ADec 1, 199253 citations

We perform extensive magnetic Feshbach spectroscopy of an ultracold mixture of fermionic

^{40}\mathrm{K}

and bosonic

^{87}\mathrm{Rb}

atoms. The magnetic-field locations of 13 interspecies resonances are used to construct a quantum collision model able to predict accurate collisional parameters for all $\mathrm{K}\text{\ensuremath{-}}\mathrm{Rb}$ isotopic pairs. In particular, we determine the interspecies

s

-wave singlet and triplet scattering lengths for the $^{40}\mathrm{K}\text{\ensuremath{-}}^{87}\mathrm{Rb}$ mixture as $(\ensuremath{-}108\ifmmode\pm\else\textpm\fi{}3){a}_{0}$ and $(\ensuremath{-}205\ifmmode\pm\else\textpm\fi{}5){a}_{0}$, respectively. We also predict accurate scattering lengths and the position of Feshbach resonances for the other $\mathrm{K}\text{\ensuremath{-}}\mathrm{Rb}$ isotopic pairs. We discuss the consequences of our results for current and future experiments with ultracold $\mathrm{K}\text{\ensuremath{-}}\mathrm{Rb}$ mixtures.

{\mathrm{H}}_{2}

. The scattering lengths and low-temperature-averaged cross sections are determined and compared with previous calculations. The scattering lengths are 0.41

{\mathit{a}}_{0}

for the singlet case and 1.91

{\mathit{a}}_{0}

for the triplet. The predicted total triplet cross section at 2 K is 5.5\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}15}$

{\mathrm{cm}}^{2}

but it could be lower, at 4.8\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}15}$

{\mathrm{cm}}^{2}

, with a different fit to the triplet potential between 12

{\mathit{a}}_{0}

and 15

{\mathit{a}}_{0}

. A more accurate triplet-state potential is needed at these separations.