Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Journal of Physics D Applied Physics

Cross-section for collisions of ultracold 7Li with Na

Volker Wippel, Christopher Binder, Laurentius Windholz

Published Jan 1, 2002• 0 citations
OpenAlex

Abstract

In a magneto-optical trap (MOT) we are able to simultaneously trap and cool 7Li and Na. We investigated the loading behavior of the cloud of Li atoms in presence of the overlapped cloud of cold Na atoms, and, by blocking the weak repumping beam for Na, compared it with the loading curve for Li atoms only. Out of these loading curves we calculated the collision cross-section of Na on Li to be 10-11 cm 3 /s.

Related papers

Simultaneous trapping of sodium and lithium in a magneto-optical trap

Volker Wippel, Christopher Binder, W. Huber +1 more

A two element magneto-optical trap (MOT) in standard configuration for Na and 7Li or 6Li is used to cool and trap Na and one Li isotope simultaneously or separately. The metal background vapor out of which the atoms are trapped comes from dispensers. The two atom clouds can be slightly shifted what makes it easy to overlap them. The number and density of the clouds were determined and the temperature measured roughly. The mutual influence of the clouds was investigated and turned out to be smaller than the noise. Preliminary experiments working towards the production of heteronuclear cold molecules by photoassociation were performed, showing the well known production of Na2 long- range molecules. Additionally, the photoionization cross- section was determined by ionizing cold atoms in the excited state by UV-laser light. The results are in reasonable agreement with data obtained elsewhere using synchrotron radiation.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Apr 9, 2001•0 citations

Simultaneous trapping of sodium and lithium in a magneto-optical trap

Volker Wippel, Christopher Binder, W. Huber +1 more

A two element magneto-optical trap (MOT) in standard configuration for Na and 7Li or 6Li is used to cool and trap Na and one Li isotope simultaneously or separately. The metal background vapor out of which the atoms are trapped comes from dispensers. The two atom clouds can be slightly shifted what makes it easy to overlap them. The number and density of the clouds were determined and the temperature measured roughly. The mutual influence of the clouds was investigated and turned out to be smaller than the noise. Preliminary experiments working towards the production of heteronuclear cold molecules by photoassociation were performed, showing the well known production of Na2 long- range molecules. Additionally, the photoionization cross- section was determined by ionizing cold atoms in the excited state by UV-laser light. The results are in reasonable agreement with data obtained elsewhere using synchrotron radiation.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Jan 1, 2001•0 citations

Ultracold collisions in a dual species 23Na-133Cs magneto-optical trap

Xu Run-Dong, Wenliang Liu, Jizhou Wu +3 more

The production and research of ultracold heteronuclear molecules have aroused the great interest recently. On the one hand, these molecules are extremely popular in experiments for exploring the collision dynamic behaviors in threshold, photoassociative spectrum and strong dipole-dipole interactions. On the other hand, ultracold polar molecules populated at deeply bound levels in the singlet ground state are the right candidates to investigate quantum memories for quantum simulation, and to study strongly interacting quantum degenerate gases. The precise knowledge of cold collision processes between two different types of alkali atoms is necessary for understanding and utilizing ultracold heteronuclear molecules, sympathetic cooling, and thus formation of two species BEC. The goal of the present investigation is to study the collisions between ultracold sodium atoms and cesium atoms. We systematically demonstrate simultaneously trapping ultracold sodium and cesium atoms in a dual-species magneto-optical trap (MOT). The sodium atom trap loss rate coefficient Na-Cs is measured as a function of Na trapping laser intensity. At low intensities, the trap loss is dominated by ground-state hyperfine-changing collisions, while at high intensities, collisions involving excited atoms are more important. A strong interspecies collision-induced loss for Na atoms in the MOT is observed. In order to obtain the trap loss coefficient Na-Cs, we proceed in two steps. First, the Cs repumping laser is blocked to avoid the formation of ultraold Cs atoms. The loading process of Na atoms is recorded when the Cs trapping laser is on. Second, the loading curves of the Na atoms are obtained as Cs atoms are present with the repumping laser beams. The total losses PNa and PNa' are acquired by fitting the two loading curves of trapped Na atoms. Thus, the trap loss coefficient Na-Cs can be derived from the difference between total losses PNa and PNa' divided by the density of the Cs atoms. The coefficient Na-Cs decreases in a range of 5-10mW/cm2, which originates from the hyperfine-state changing (HFC) collision. A Doppler model is used to calculate the Na atom trap depth, in that the atom trap depth and exoergic energy determine the behavior of the collisional trap loss rate coefficient. The three corresponding calculated critical intensities of Na trapping laser are 7.98, 14.82, 16.2 mW/cm2 respectively in the Na-Cs HFC collision process. The first calculated critical intensity value agrees well with the experimental result. Our work provides a valuable insight into HFC collision between Na and Cs atoms and also paves the way for the production of ultracold NaCs molecules using Photoassociation (PA) technology. Furthermore, the experimental results lay a great basis for the obtainments of high sensitive heteronuclear NaCs molecular PA spectrum and the creation of deeply bound ground state molecules.

Acta Physica Sinica•Jan 1, 2016•1 citation

Photoionization for Na and Li cold atoms in a MOT

Volker Wippel, C. Binder, W. Huber +4 more

Summary form only given. Photoionization of cold atoms in their first excited state has been applied to measure the photoionization cross section in rubidium magneto-optical trap (MOT), and cesium MOT. The modifications of the MOT loading rate and of the steady state number of trapped atoms allow one to measure the dependence of the cold atom photoionization cross section on the laser wavelength for absorption from the excited atomic state. We report here on measurements of photoionization cross-sections of both laser-cooled sodium and lithium atoms at various photoionization wavelengths.

Conference on Lasers and Electro-Optics•Aug 29, 2005•0 citations

Trap loss collisions of6Li and7Li with23Na in a combined magneto-optical trap

Gerald Auböck, C Binder, L. Holler +5 more

We investigated heteronuclear inelastic cold collisions in a mixed-species Li–Na magneto-optical trap, where the Li trap loss from collisions with Na was measured. Experimental results for the rate coefficient β Na Li for the isotopes 6 Li as well as 7 Li as a function of the Li-MOT laser intensity are presented. Furthermore, we discuss some unique characteristics of cold collisions of Na and Li which arise from (1) the very small spin–orbit splitting of Li, (2) the very small C 6 coefficients of the Na(3 2 S) + Li(2 2 P) asymptotes and (3) the very small and inverted hyperfine structure of Li.

Journal of Physics B Atomic Molecular and Optical Physics•Sep 25, 2006•9 citations

A versatile apparatus for simultaneous trapping of multiple species of ultracold atoms and ions to enable studies of low energy collisions and cold chemistry

Bubai Rahaman, Satyabrata Baidya, Sourav Dutta

We describe an apparatus where many species of ultracold atoms can be simultaneously trapped and overlapped with many species of ions in a Paul trap. Several design innovations are made to increase the versatility of the apparatus while keeping the size and cost reasonable. We demonstrate the operation of a three-dimensional (3D) magneto-optical trap (MOT) of 7Li using a single external cavity diode laser. The 7Li MOT is loaded from an atomic beam, with atoms slowed using a Zeeman slower designed to work simultaneously for Li and Sr. The operation of a 3D MOT of 133Cs, loaded from a 2D MOT, is demonstrated, and provisions for MOTs of Rb and K in the same vacuum manifold exist. We demonstrate the trapping of 7Li+ and 133Cs+ at different settings of the Paul trap and their detection using an integrated time-of-flight mass spectrometer. We present results on low energy neutral-neutral collisions (133Cs-133Cs, 7Li-7Li, and 133Cs-7Li collisions) and charge-neutral collisions (133Cs+-133Cs and 7Li+-7Li collisions). We show evidence of sympathetic cooling of 7Li+ (133Cs+) due to collisions with the ultracold 7Li (133Cs).

arXiv:2401.11233•The Journal of Chemical Physics•Feb 13, 2024•1 citation
In a magneto-optical trap (MOT) we are able to simultaneously trap and cool 7Li and Na. We investigated the loading behavior of the cloud of Li atoms in presence of the overlapped cloud of cold Na atoms, and, by blocking the weak repumping beam for Na, compared it with the loading curve for Li atoms only. Out of these loading curves we calculated the collision cross-section of Na on Li to be 10-11 cm
3
/s.
A two element magneto-optical trap (MOT) in standard configuration for Na and 7Li or 6Li is used to cool and trap Na and one Li isotope simultaneously or separately. The metal background vapor out of which the atoms are trapped comes from dispensers. The two atom clouds can be slightly shifted what makes it easy to overlap them. The number and density of the clouds were determined and the temperature measured roughly. The mutual influence of the clouds was investigated and turned out to be smaller than the noise. Preliminary experiments working towards the production of heteronuclear cold molecules by photoassociation were performed, showing the well known production of Na2 long- range molecules. Additionally, the photoionization cross- section was determined by ionizing cold atoms in the excited state by UV-laser light. The results are in reasonable agreement with data obtained elsewhere using synchrotron radiation.
A two element magneto-optical trap (MOT) in standard configuration for Na and 7Li or 6Li is used to cool and trap Na and one Li isotope simultaneously or separately. The metal background vapor out of which the atoms are trapped comes from dispensers. The two atom clouds can be slightly shifted what makes it easy to overlap them. The number and density of the clouds were determined and the temperature measured roughly. The mutual influence of the clouds was investigated and turned out to be smaller than the noise. Preliminary experiments working towards the production of heteronuclear cold molecules by photoassociation were performed, showing the well known production of Na2 long- range molecules. Additionally, the photoionization cross- section was determined by ionizing cold atoms in the excited state by UV-laser light. The results are in reasonable agreement with data obtained elsewhere using synchrotron radiation.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
The production and research of ultracold heteronuclear molecules have aroused the great interest recently. On the one hand, these molecules are extremely popular in experiments for exploring the collision dynamic behaviors in threshold, photoassociative spectrum and strong dipole-dipole interactions. On the other hand, ultracold polar molecules populated at deeply bound levels in the singlet ground state are the right candidates to investigate quantum memories for quantum simulation, and to study strongly interacting quantum degenerate gases. The precise knowledge of cold collision processes between two different types of alkali atoms is necessary for understanding and utilizing ultracold heteronuclear molecules, sympathetic cooling, and thus formation of two species BEC. The goal of the present investigation is to study the collisions between ultracold sodium atoms and cesium atoms. We systematically demonstrate simultaneously trapping ultracold sodium and cesium atoms in a dual-species magneto-optical trap (MOT). The sodium atom trap loss rate coefficient Na-Cs is measured as a function of Na trapping laser intensity. At low intensities, the trap loss is dominated by ground-state hyperfine-changing collisions, while at high intensities, collisions involving excited atoms are more important. A strong interspecies collision-induced loss for Na atoms in the MOT is observed. In order to obtain the trap loss coefficient Na-Cs, we proceed in two steps. First, the Cs repumping laser is blocked to avoid the formation of ultraold Cs atoms. The loading process of Na atoms is recorded when the Cs trapping laser is on. Second, the loading curves of the Na atoms are obtained as Cs atoms are present with the repumping laser beams. The total losses PNa and PNa' are acquired by fitting the two loading curves of trapped Na atoms. Thus, the trap loss coefficient Na-Cs can be derived from the difference between total losses PNa and PNa' divided by the density of the Cs atoms. The coefficient Na-Cs decreases in a range of 5-10mW/cm2, which originates from the hyperfine-state changing (HFC) collision. A Doppler model is used to calculate the Na atom trap depth, in that the atom trap depth and exoergic energy determine the behavior of the collisional trap loss rate coefficient. The three corresponding calculated critical intensities of Na trapping laser are 7.98, 14.82, 16.2 mW/cm2 respectively in the Na-Cs HFC collision process. The first calculated critical intensity value agrees well with the experimental result. Our work provides a valuable insight into HFC collision between Na and Cs atoms and also paves the way for the production of ultracold NaCs molecules using Photoassociation (PA) technology. Furthermore, the experimental results lay a great basis for the obtainments of high sensitive heteronuclear NaCs molecular PA spectrum and the creation of deeply bound ground state molecules.
Summary form only given. Photoionization of cold atoms in their first excited state has been applied to measure the photoionization cross section in rubidium magneto-optical trap (MOT), and cesium MOT. The modifications of the MOT loading rate and of the steady state number of trapped atoms allow one to measure the dependence of the cold atom photoionization cross section on the laser wavelength for absorption from the excited atomic state. We report here on measurements of photoionization cross-sections of both laser-cooled sodium and lithium atoms at various photoionization wavelengths.
We investigated heteronuclear inelastic cold collisions in a mixed-species Li–Na magneto-optical trap, where the Li trap loss from collisions with Na was measured. Experimental results for the rate coefficient β Na Li for the isotopes 6 Li as well as 7 Li as a function of the Li-MOT laser intensity are presented. Furthermore, we discuss some unique characteristics of cold collisions of Na and Li which arise from (1) the very small spin–orbit splitting of Li, (2) the very small C 6 coefficients of the Na(3 2 S) + Li(2 2 P) asymptotes and (3) the very small and inverted hyperfine structure of Li.
We describe an apparatus where many species of ultracold atoms can be simultaneously trapped and overlapped with many species of ions in a Paul trap. Several design innovations are made to increase the versatility of the apparatus while keeping the size and cost reasonable. We demonstrate the operation of a three-dimensional (3D) magneto-optical trap (MOT) of 7Li using a single external cavity diode laser. The 7Li MOT is loaded from an atomic beam, with atoms slowed using a Zeeman slower designed to work simultaneously for Li and Sr. The operation of a 3D MOT of 133Cs, loaded from a 2D MOT, is demonstrated, and provisions for MOTs of Rb and K in the same vacuum manifold exist. We demonstrate the trapping of 7Li+ and 133Cs+ at different settings of the Paul trap and their detection using an integrated time-of-flight mass spectrometer. We present results on low energy neutral-neutral collisions (133Cs-133Cs, 7Li-7Li, and 133Cs-7Li collisions) and charge-neutral collisions (133Cs+-133Cs and 7Li+-7Li collisions). We show evidence of sympathetic cooling of 7Li+ (133Cs+) due to collisions with the ultracold 7Li (133Cs).