Physical Review A

Quantum statistical effect on ionizing collisions of ultracold metastable Kr isotopes

Hidetoshi Katori, Hideyuki Kunugita, T. Ido

Published Dec 1, 1995• 14 citations

Abstract

Ultracold ionizing collisions of laser-cooled Kr isotopes in the 1${\mathit{s}}_{5}$[4${\mathit{p}}^{5}$5s${:}^{3}$${\mathit{P}}_{2}$] metastable state are investigated. When the collision energy is reduced below the p-wave centrifugal barrier of 80 \ensuremath{\mu}K, the ratio of the ionizing collision rate between polarized and unpolarized $^{83}\mathrm{Kr}$ atoms is found to decrease. This is a direct evidence of the quantum interference of two identical Fermi particles. The experimental results are compared with the calculation based on the simplified inelastic collision theory.

DOI: 10.1103/physreva.52.r4324

Related papers

Spin polarization and quantum-statistical effects in ultracold ionizing collisions

Chad Orzel, M. Walhout, Uwe Sterr +2 more

Physical Review AMar 1, 199939 citations

Laser-Induced Ionizing Collisions of Ultracold Krypton Gas in the 1s5 Metastable State

Hidetoshi Katori, Fujio Shimizu

Physical Review LettersNov 7, 199458 citations

Ultracold collisions and optical shielding in metastable xenon

Kalle‐Antti Suominen, Keith R. Burnett, Paul S. Julienne +5 more

Physical Review AMar 1, 199631 citations

Ultracold homonuclear and heteronuclear collisions in metastable helium

Daniel Cocks, Ian B. Whittingham, G. Peach

arXiv:1904.01281Physical Review AJun 28, 20194 citations

Homonuclear ionizing collisions of laser-cooled metastable helium atoms

R. J. W. Stas, J. M. McNamara, W. Hogervorst +1 more

arXiv:cond-mat/0601414Physical Review AMar 14, 200623 citations

Heteronuclear collisions between laser-cooled metastable neon atoms

Jan Schütz, Thomas Feldker, Holger John +1 more

arXiv:1208.5719Physical Review AAug 24, 20124 citations

Physical Review A

Quantum statistical effect on ionizing collisions of ultracold metastable Kr isotopes

Hidetoshi Katori, Hideyuki Kunugita, T. Ido

Published Dec 1, 1995• 14 citations

Publisher

Abstract

Ultracold ionizing collisions of laser-cooled Kr isotopes in the 1

{\mathit{s}}_{5}

{\mathit{p}}^{5}

{:}^{3}$${\mathit{P}}_{2}

] metastable state are investigated. When the collision energy is reduced below the p-wave centrifugal barrier of 80 \ensuremath{\mu}K, the ratio of the ionizing collision rate between polarized and unpolarized

^{83}\mathrm{Kr}

atoms is found to decrease. This is a direct evidence of the quantum interference of two identical Fermi particles. The experimental results are compared with the calculation based on the simplified inelastic collision theory.

DOI: 10.1103/physreva.52.r4324

Related papers

Spin polarization and quantum-statistical effects in ultracold ionizing collisions

Chad Orzel, M. Walhout, Uwe Sterr +2 more

We have measured ultracold ionizing collision rates for three bosonic ${(}^{132}\mathrm{Xe},{}^{134}\mathrm{Xe},$ and ${}^{136}\mathrm{Xe})$ and two fermionic ${(}^{129}\mathrm{Xe}$ and ${}^{131}\mathrm{Xe})$ isotopes of xenon in the $6s[3/2{]}_{2}$ metastable state, for both spin-polarized and unpolarized samples. For unpolarized samples at temperatures above the p-wave centrifugal barrier $(\ensuremath{\sim}39 \ensuremath{\mu}\mathrm{K}),$ we find that collision rates for all isotopes are identical. Quantum-statistical effects forbid s-wave collisions for spin-polarized fermions, giving rise to significant differences between bosonic and fermionic isotopes below the p-wave barrier. We present a technique for measuring collision rates at temperatures below $1 \ensuremath{\mu}\mathrm{K},$ and find that the ratio of polarized to unpolarized collision rates for fermions decreases by a factor of 2 at low temperatures, while the ratio for bosons increases by $50%.$ We find no evidence of an overall reduction in the collision rate for spin-polarized samples, as has been observed in metastable helium. These results are explained using a simple theoretical model of transmission and quantum reflection off long-range interatomic potentials.We have measured ultracold ionizing collision rates for three bosonic ${(}^{132}\mathrm{Xe},{}^{134}\mathrm{Xe},$ and ${}^{136}\mathrm{Xe})$ and two fermionic ${(}^{129}\mathrm{Xe}$ and ${}^{131}\mathrm{Xe})$ isotopes of xenon in the $6s[3/2{]}_{2}$ metastable state, for both spin-polarized and unpolarized samples. For unpolarized samples at temperatures above the p-wave centrifugal barrier $(\ensuremath{\sim}39 \ensuremath{\mu}\mathrm{K}),$ we find that collision rates for all isotopes are identical. Quantum-statistical effects forbid s-wave collisions for spin-polarized fermions, giving rise to significant differences between bosonic and fermionic isotopes below the p-wave barrier. We present a technique for measuring collision rates at temperatures below $1 \ensuremath{\mu}\mathrm{K},$ and find that the ratio of polarized to unpolarized collision rates for fermions decreases by a factor of 2 at low temperatures, while the ratio for bosons increases by $50%.$ We find no evidence of an overall reduction in the collision rate for spin-polarized samples, as has been observed in metastable helium. These results are explained using a simple theoretical model of transmission and quantum reflection off long-range interatomic potentials.

Physical Review AMar 1, 199939 citations

Laser-Induced Ionizing Collisions of Ultracold Krypton Gas in the 1s5 Metastable State

Hidetoshi Katori, Fujio Shimizu

The line shape of laser-induced ionizing collisions of ultracold Kr gas is investigated near the ${1s}_{5}[4p^{5}5s:^{3}P_{2}]$ and ${2p}_{9}[4p^{5}5p:^{3}D_{3}]$ transition. The rate increases several times when the laser is red tuned by a few times of the natural width, while it sharply decreases for a slight blue detuning. This frequency dependence of the collision rate is due to the collision dynamics characteristic of ultracold atoms in a near-resonant light. Our experimental results on metastable Kr atoms show a good qualitative agreement with semiclassical Monte Carlo simulation of the cold collision dynamics.The line shape of laser-induced ionizing collisions of ultracold Kr gas is investigated near the ${1s}_{5}[4p^{5}5s:^{3}P_{2}]$ and ${2p}_{9}[4p^{5}5p:^{3}D_{3}]$ transition. The rate increases several times when the laser is red tuned by a few times of the natural width, while it sharply decreases for a slight blue detuning. This frequency dependence of the collision rate is due to the collision dynamics characteristic of ultracold atoms in a near-resonant light. Our experimental results on metastable Kr atoms show a good qualitative agreement with semiclassical Monte Carlo simulation of the cold collision dynamics.

Physical Review LettersNov 7, 199458 citations

Ultracold collisions and optical shielding in metastable xenon

Kalle‐Antti Suominen, Keith R. Burnett, Paul S. Julienne +5 more

Collisions between laser-cooled metastable xenon atoms in the presence of laser fields provide a good experimental test for ultracold collision theories as the observed ionization can be directly linked to the atomic binary collisions. Hyperfine structure is not present for the even isotopes ${\mathrm{Xe}}^{132}$ and ${\mathrm{Xe}}^{136}$ , which simplifies the theoretical work. We present our results and show how these and the results presented in Walhout et al. [Phys. Rev. Lett. 74, 605 (1995)] can be interpreted with suitably adapted two-state models. Our approach suggests one possibility why the strong shielding of collisions predicted by the simple two-state model of Suominen et al. [Phys. Rev. A 51, 1446 (1995)] has not been achieved in the xenon experiment. \textcopyright{} 1996 The American Physical Society.Collisions between laser-cooled metastable xenon atoms in the presence of laser fields provide a good experimental test for ultracold collision theories as the observed ionization can be directly linked to the atomic binary collisions. Hyperfine structure is not present for the even isotopes ${\mathrm{Xe}}^{132}$ and ${\mathrm{Xe}}^{136}$, which simplifies the theoretical work. We present our results and show how these and the results presented in Walhout et al. [Phys. Rev. Lett. 74, 605 (1995)] can be interpreted with suitably adapted two-state models. Our approach suggests one possibility why the strong shielding of collisions predicted by the simple two-state model of Suominen et al. [Phys. Rev. A 51, 1446 (1995)] has not been achieved in the xenon experiment. \textcopyright{} 1996 The American Physical Society.

Physical Review AMar 1, 199631 citations

Ultracold homonuclear and heteronuclear collisions in metastable helium

Daniel Cocks, Ian B. Whittingham, G. Peach

Scattering and ionizing cross sections and rates are calculated for ultracold collisions between metastable helium atoms using a fully quantum-mechanical close-coupled formalism. Homonuclear collisions of the bosonic $^{4}\mathrm{He}^{*}+^{4}\mathrm{He}^{*}$ and fermionic $^{3}\mathrm{He}^{*}+^{3}\mathrm{He}^{*}$ systems, and heteronuclear collisions of the mixed $^{3}\mathrm{He}^{*}+^{4}\mathrm{He}^{*}$ system, are investigated over the temperature range 1 $\ensuremath{\mu}\mathrm{K}$ to 1 K. Carefully constructed Born-Oppenheimer molecular potentials are used to describe the electrostatic interaction between the colliding atoms, and complex optical potentials to represent loss through ionization from the ${}^{1,3}\mathrm{\ensuremath{\Sigma}}$ states. Magnetic spin-dipole-mediated transitions from the ${}^{5}\mathrm{\ensuremath{\Sigma}}$ state are included and results reported for spin-polarized and unpolarized systems. Comparisons are made with experimental results, previous semiclassical models, and a perturbed single-channel model.Scattering and ionizing cross sections and rates are calculated for ultracold collisions between metastable helium atoms using a fully quantum-mechanical close-coupled formalism. Homonuclear collisions of the bosonic $^{4}\mathrm{He}^{*}+^{4}\mathrm{He}^{*}$ and fermionic $^{3}\mathrm{He}^{*}+^{3}\mathrm{He}^{*}$ systems, and heteronuclear collisions of the mixed $^{3}\mathrm{He}^{*}+^{4}\mathrm{He}^{*}$ system, are investigated over the temperature range 1 $\ensuremath{\mu}\mathrm{K}$ to 1 K. Carefully constructed Born-Oppenheimer molecular potentials are used to describe the electrostatic interaction between the colliding atoms, and complex optical potentials to represent loss through ionization from the ${}^{1,3}\mathrm{\ensuremath{\Sigma}}$ states. Magnetic spin-dipole-mediated transitions from the ${}^{5}\mathrm{\ensuremath{\Sigma}}$ state are included and results reported for spin-polarized and unpolarized systems. Comparisons are made with experimental results, previous semiclassical models, and a perturbed single-channel model.

arXiv:1904.01281Physical Review AJun 28, 20194 citations

Homonuclear ionizing collisions of laser-cooled metastable helium atoms

R. J. W. Stas, J. M. McNamara, W. Hogervorst +1 more

We present a theoretical and experimental investigation of homonuclear ionizing collisions of laser-cooled metastable $(2\phantom{\rule{0.2em}{0ex}}^{3}S_{1})$ helium atoms, considering both the fermionic $^{3}\mathrm{He}$ and bosonic $^{4}\mathrm{He}$ isotopes. The theoretical description combines quantum threshold behavior, Wigner's spin-conservation rule, and quantum-statistical symmetry requirements in a single-channel model, complementing a more complete close-coupling theory that has been reported for collisions of metastable $^{4}\mathrm{He}$ atoms. The model is supported with measurements (in the absence of light fields) of ionization rates in magneto-optically trapped samples that contain about $3\ifmmode\times\else\texttimes\fi{}{10}^{8}$ atoms of a single isotope. The ionization rates are determined from measurements of trap loss due to light-assisted collisions combined with comparative measurements of the ion production rate in the absence and presence of trapping light. Theory and experiment show good agreement.We present a theoretical and experimental investigation of homonuclear ionizing collisions of laser-cooled metastable $(2\phantom{\rule{0.2em}{0ex}}^{3}S_{1})$ helium atoms, considering both the fermionic $^{3}\mathrm{He}$ and bosonic $^{4}\mathrm{He}$ isotopes. The theoretical description combines quantum threshold behavior, Wigner's spin-conservation rule, and quantum-statistical symmetry requirements in a single-channel model, complementing a more complete close-coupling theory that has been reported for collisions of metastable $^{4}\mathrm{He}$ atoms. The model is supported with measurements (in the absence of light fields) of ionization rates in magneto-optically trapped samples that contain about $3\ifmmode\times\else\texttimes\fi{}{10}^{8}$ atoms of a single isotope. The ionization rates are determined from measurements of trap loss due to light-assisted collisions combined with comparative measurements of the ion production rate in the absence and presence of trapping light. Theory and experiment show good agreement.

arXiv:cond-mat/0601414Physical Review AMar 14, 200623 citations

Heteronuclear collisions between laser-cooled metastable neon atoms

Jan Schütz, Thomas Feldker, Holger John +1 more

We investigate heteronuclear collisions in isotope mixtures of laser-cooled metastable ( ${}^{3}\phantom{\rule{-0.16em}{0ex}}{P}_{2}$ ) neon. Experiments are performed with spin-polarized atoms in a magnetic trap for all two-isotope combinations of the stable neon isotopes ${}^{20}$ Ne, ${}^{21}$ Ne, and ${}^{22}$ Ne. We determine the rate coefficients for heteronuclear ionizing collisions to ${\ensuremath{\beta}}_{21,20}=(3.9\ifmmode\pm\else\textpm\fi{}2.7)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}11}$ cm ${}^{3}$ /s, ${\ensuremath{\beta}}_{22,20}=(2.6\ifmmode\pm\else\textpm\fi{}0.7)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}11}$ cm ${}^{3}$ /s, and ${\ensuremath{\beta}}_{21,22}=(3.9\ifmmode\pm\else\textpm\fi{}1.9)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}11}$ cm ${}^{3}$ /s. We also study heteronuclear elastic collision processes and give upper bounds for heteronuclear thermal relaxation cross sections. This work significantly extends the limited available experimental data on heteronuclear ionizing collisions for laser-cooled atoms involving one or more rare gas atoms in a metastable state.We investigate heteronuclear collisions in isotope mixtures of laser-cooled metastable (${}^{3}\phantom{\rule{-0.16em}{0ex}}{P}_{2}$) neon. Experiments are performed with spin-polarized atoms in a magnetic trap for all two-isotope combinations of the stable neon isotopes ${}^{20}$Ne, ${}^{21}$Ne, and ${}^{22}$Ne. We determine the rate coefficients for heteronuclear ionizing collisions to ${\ensuremath{\beta}}_{21,20}=(3.9\ifmmode\pm\else\textpm\fi{}2.7)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}11}$ cm${}^{3}$/s, ${\ensuremath{\beta}}_{22,20}=(2.6\ifmmode\pm\else\textpm\fi{}0.7)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}11}$ cm${}^{3}$/s, and ${\ensuremath{\beta}}_{21,22}=(3.9\ifmmode\pm\else\textpm\fi{}1.9)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}11}$ cm${}^{3}$/s. We also study heteronuclear elastic collision processes and give upper bounds for heteronuclear thermal relaxation cross sections. This work significantly extends the limited available experimental data on heteronuclear ionizing collisions for laser-cooled atoms involving one or more rare gas atoms in a metastable state.

arXiv:1208.5719Physical Review AAug 24, 20124 citations

Ultracold ionizing collisions of laser-cooled Kr isotopes in the 1

{\mathit{s}}_{5}

{\mathit{p}}^{5}

{:}^{3}$${\mathit{P}}_{2}

^{83}\mathrm{Kr}

We have measured ultracold ionizing collision rates for three bosonic

{(}^{132}\mathrm{Xe},{}^{134}\mathrm{Xe},

and

{}^{136}\mathrm{Xe})

and two fermionic

{(}^{129}\mathrm{Xe}

and

{}^{131}\mathrm{Xe})

isotopes of xenon in the

6s[3/2{]}_{2}

metastable state, for both spin-polarized and unpolarized samples. For unpolarized samples at temperatures above the p-wave centrifugal barrier $(\ensuremath{\sim}39 \ensuremath{\mu}\mathrm{K}),$ we find that collision rates for all isotopes are identical. Quantum-statistical effects forbid s-wave collisions for spin-polarized fermions, giving rise to significant differences between bosonic and fermionic isotopes below the p-wave barrier. We present a technique for measuring collision rates at temperatures below $1 \ensuremath{\mu}\mathrm{K},$ and find that the ratio of polarized to unpolarized collision rates for fermions decreases by a factor of 2 at low temperatures, while the ratio for bosons increases by

50%.

We find no evidence of an overall reduction in the collision rate for spin-polarized samples, as has been observed in metastable helium. These results are explained using a simple theoretical model of transmission and quantum reflection off long-range interatomic potentials.

The line shape of laser-induced ionizing collisions of ultracold Kr gas is investigated near the

{1s}_{5}[4p^{5}5s:^{3}P_{2}]

and

{2p}_{9}[4p^{5}5p:^{3}D_{3}]

transition. The rate increases several times when the laser is red tuned by a few times of the natural width, while it sharply decreases for a slight blue detuning. This frequency dependence of the collision rate is due to the collision dynamics characteristic of ultracold atoms in a near-resonant light. Our experimental results on metastable Kr atoms show a good qualitative agreement with semiclassical Monte Carlo simulation of the cold collision dynamics.

{\mathrm{Xe}}^{132}

and

{\mathrm{Xe}}^{136}

, which simplifies the theoretical work. We present our results and show how these and the results presented in Walhout et al. [Phys. Rev. Lett. 74, 605 (1995)] can be interpreted with suitably adapted two-state models. Our approach suggests one possibility why the strong shielding of collisions predicted by the simple two-state model of Suominen et al. [Phys. Rev. A 51, 1446 (1995)] has not been achieved in the xenon experiment. \textcopyright{} 1996 The American Physical Society.

^{4}\mathrm{He}^{*}+^{4}\mathrm{He}^{*}

and fermionic

^{3}\mathrm{He}^{*}+^{3}\mathrm{He}^{*}

systems, and heteronuclear collisions of the mixed

^{3}\mathrm{He}^{*}+^{4}\mathrm{He}^{*}

system, are investigated over the temperature range 1 $\ensuremath{\mu}\mathrm{K}$ to 1 K. Carefully constructed Born-Oppenheimer molecular potentials are used to describe the electrostatic interaction between the colliding atoms, and complex optical potentials to represent loss through ionization from the ${}^{1,3}\mathrm{\ensuremath{\Sigma}}$ states. Magnetic spin-dipole-mediated transitions from the ${}^{5}\mathrm{\ensuremath{\Sigma}}$ state are included and results reported for spin-polarized and unpolarized systems. Comparisons are made with experimental results, previous semiclassical models, and a perturbed single-channel model.

We present a theoretical and experimental investigation of homonuclear ionizing collisions of laser-cooled metastable

(2\phantom{\rule{0.2em}{0ex}}^{3}S_{1})

helium atoms, considering both the fermionic

^{3}\mathrm{He}

and bosonic

^{4}\mathrm{He}

isotopes. The theoretical description combines quantum threshold behavior, Wigner's spin-conservation rule, and quantum-statistical symmetry requirements in a single-channel model, complementing a more complete close-coupling theory that has been reported for collisions of metastable

^{4}\mathrm{He}

atoms. The model is supported with measurements (in the absence of light fields) of ionization rates in magneto-optically trapped samples that contain about $3\ifmmode\times\else\texttimes\fi{}{10}^{8}$ atoms of a single isotope. The ionization rates are determined from measurements of trap loss due to light-assisted collisions combined with comparative measurements of the ion production rate in the absence and presence of trapping light. Theory and experiment show good agreement.

We investigate heteronuclear collisions in isotope mixtures of laser-cooled metastable (

{}^{3}\phantom{\rule{-0.16em}{0ex}}{P}_{2}

) neon. Experiments are performed with spin-polarized atoms in a magnetic trap for all two-isotope combinations of the stable neon isotopes

{}^{20}

Ne,

{}^{21}

Ne, and

{}^{22}

Ne. We determine the rate coefficients for heteronuclear ionizing collisions to ${\ensuremath{\beta}}_{21,20}=(3.9\ifmmode\pm\else\textpm\fi{}2.7)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}11}$ cm

{}^{3}

/s, ${\ensuremath{\beta}}_{22,20}=(2.6\ifmmode\pm\else\textpm\fi{}0.7)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}11}$ cm

{}^{3}

/s, and ${\ensuremath{\beta}}_{21,22}=(3.9\ifmmode\pm\else\textpm\fi{}1.9)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}11}$ cm

{}^{3}

/s. We also study heteronuclear elastic collision processes and give upper bounds for heteronuclear thermal relaxation cross sections. This work significantly extends the limited available experimental data on heteronuclear ionizing collisions for laser-cooled atoms involving one or more rare gas atoms in a metastable state.