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

Quantum Electronics and Laser Science Conference

Collisional studies in cold binary mixtures

Gustavo Deczka Telles, Wilton Garcia, L. S. Aguiar, Sérgio Ricardo Muniz, Luís Gustavo Marcassa, Vanderlei Salvador Bagnato

Published Nov 13, 2002• 0 citations
Publisher

Abstract

Summary form only given. We present a set of experimental results of trap loss rate for the following mixtures: Na-Rb, K-Rb, Na-K, Rb-Cs and Cs-K. The analysis of our data set allows us to conclude that radiative escape is the main loss mechanism and we observed the significant contribution of the double-excited potential (both atoms excited) for the losses on the studied species. We also have applied an adapted Gallagher-Pritchard model to understand the importance of the reduced mass and the trap depth.

DOI
10.1109/qels.2001.962229

Related papers

Collisional losses in a K-Rb cold mixture

Luís Gustavo Marcassa, Gustavo Deczka Telles, Sérgio Ricardo Muniz +1 more

We have observed a heteronuclear trap loss rate for a mixture of trapped ${}^{39}\mathrm{K}$ and ${}^{85}\mathrm{Rb}$ atoms. Our results indicate that hyperfine changing collision and radiative escape dominate in the low and high intensity regimes, respectively. They are also consistent with radiative escape taking place with the participation of the doubly excited state potential $({\mathrm{K}}^{*}\ensuremath{-}{\mathrm{Rb}}^{*}).$ A Gallagher-Pritchard model taking into account the doubly excited channel was implemented, reproducing the experimental results well qualitatively. The values obtained for the cross species trap loss indicate possibilities of future experiments with this mixture.

Physical Review A•Dec 13, 2000•45 citations

Exoergic cold collisions in a mixture of K-Rb

Gustavo Deczka Telles, Sérgio Ricardo Muniz, Vanderlei Salvador Bagnato +1 more

Summary form only given. Several theoretical studies have recently been published, proposing a new series of experiments involving two different species of atoms trapped together: two species BEC and heteronuclear cold collisions. As in the case of single species, these experiments require that samples be obtained at high density. Therefore, an important step is the understanding and possible control of heteronuclear collisions. In this context, the study of trap loss in a binary mixture comes at the right time and is significant. We report on a measurement of cross species trap loss rate for a system composed of /sup 39/K and /sup 85/Rb, and we implement an adapted Gallagher-Pritchard model to attempt to explain the experimental observations.

Quantum Electronics and Laser Science Conference•Jan 1, 2000•0 citations

Inelastic cold collisions of a Na/Rb mixture in a magneto-optical trap

Gustavo Deczka Telles, Luís Gustavo Marcassa, Sérgio Ricardo Muniz +4 more

We report results on inelastic cold collisions for a mixed species magneto-optical trap containing Na and Rb. The rate of collisional trap loss of Na is due to different contributions: Na-Na and Na-Rb collisions. Both parts are investigated with respect to trap laser intensity and frequency. The observations are explained based on a Gallagher-Pritchard model. Possibilities for studies and applications involving mixed species traps are discussed.

Physical Review A•Jan 1, 1999•49 citations

Cold collisions of ground- and excited-state alkali-metal atoms

Paul S. Julienne, J. Vigué

This paper examines two collisional mechanisms by which cold alkali-metal atoms can escape from a neutral-atom trap, due to collison of excited- and ground-state atoms. One is fine-structure-changing collisions, by which the atoms are heated by the amount of the fine-structure splitting. The other produces hot ground-state atoms following emission of a red-shifted photon during the course of a collision. A rate expression is obtained that applies to both normal and ultracold temperatures (1 mK). This expression assumes a canonical distribution of initial states, low-intensity excitation, and a semiclassical treatment of the survival probability relative to excited-state decay during the long time of the ultracold collision, and uses fine-structure-changing probabilities found by quantum scattering calculations. The known properties of the attractive molecular states of the alkaline-metal dimers are used to identify and calculate the probabilities for the specific mechanisms. We conclude that the earlier semiclassical analysis by Dashevskaya [Opt. Spectrosk. 46, 423 (1979)] of the fine-structure-changing mechanisms for the various alkali-metal species is qualitatively correct. We present quantum-mechanical calculations of the rate coefficient for fine-structure-changing collisions between ground- and excited-state Cs atoms from 1000 K to 100 \ensuremath{\mu}K. Collision-rate coefficients for the trap-loss processes are calculated for pairs of Li, Na, K, Rb, and Cs atoms at low temperature. There is a wide variation of predicted loss rate among alkali-metal species from the fastest for K and the slowest for Li. Retardation corrections to molecular lifetimes must be taken into account to predict the correct rate coefficients for Na, K, and Rb. Good agreement is obtained with the observed trap loss rate in a Cs trap.

Physical Review A•Oct 1, 1991•183 citations

Dependence of rubidium trap loss collisions on trap laser intensity and detuning

V. Sánchez-Villicaña, S. D. Gensemer, Wenko Süptitz +1 more

Summary form only given. Inelastic collisions between cold atoms can lead to their ejection from the laser trap that confines them. Understanding these trap loss collisions is important to efforts aimed at high densities of cold atoms. Previously we have observed pronounced differences in the collisional behavior of the two isotopes, /sup 85/Rb and /sup 87/Rb, for the trap laser tuned one natural linewidth below resonance. We have extended our measurements for both isotopes to smaller and larger detunings in an effort to separate the various contributions to the trap loss rate.

Quantum Electronics and Laser Science Conference•Jun 7, 1996•0 citations

Evidence of a two-color trap-loss channel

Gustavo Deczka Telles, L. S. Aguiar, Luís Gustavo Marcassa +1 more

We have previously reported experimental results on the trap-loss rate for a mixed species magneto-optical trap involving a pair of Na and Rb atoms [Phys. Rev. A 59, R23 (1999)]. The predicted dependence for the heteronuclear trap-loss rate as a function of laser detuning assuming a colliding pair of ground-state--excited-state atoms fails to explain the experimental results. Further investigation has shown that our observations are consistent if one assumes a loss channel involving an excited state--excited-state colliding pair of atoms. Here we present the model and discuss the physical interpretation applied to our previous experimental results. The present interpretation opens up other ways to understand the trap-loss mechanisms.

Physical Review A•Aug 27, 2002•7 citations
Summary form only given. We present a set of experimental results of trap loss rate for the following mixtures: Na-Rb, K-Rb, Na-K, Rb-Cs and Cs-K. The analysis of our data set allows us to conclude that radiative escape is the main loss mechanism and we observed the significant contribution of the double-excited potential (both atoms excited) for the losses on the studied species. We also have applied an adapted Gallagher-Pritchard model to understand the importance of the reduced mass and the trap depth.
We have observed a heteronuclear trap loss rate for a mixture of trapped 39K{}^{39}\mathrm{K}39K and 85Rb{}^{85}\mathrm{Rb}85Rb atoms. Our results indicate that hyperfine changing collision and radiative escape dominate in the low and high intensity regimes, respectively. They are also consistent with radiative escape taking place with the participation of the doubly excited state potential $({\mathrm{K}}^{*}\ensuremath{-}{\mathrm{Rb}}^{*}).$ A Gallagher-Pritchard model taking into account the doubly excited channel was implemented, reproducing the experimental results well qualitatively. The values obtained for the cross species trap loss indicate possibilities of future experiments with this mixture.
Summary form only given. Several theoretical studies have recently been published, proposing a new series of experiments involving two different species of atoms trapped together: two species BEC and heteronuclear cold collisions. As in the case of single species, these experiments require that samples be obtained at high density. Therefore, an important step is the understanding and possible control of heteronuclear collisions. In this context, the study of trap loss in a binary mixture comes at the right time and is significant. We report on a measurement of cross species trap loss rate for a system composed of /sup 39/K and /sup 85/Rb, and we implement an adapted Gallagher-Pritchard model to attempt to explain the experimental observations.
This paper examines two collisional mechanisms by which cold alkali-metal atoms can escape from a neutral-atom trap, due to collison of excited- and ground-state atoms. One is fine-structure-changing collisions, by which the atoms are heated by the amount of the fine-structure splitting. The other produces hot ground-state atoms following emission of a red-shifted photon during the course of a collision. A rate expression is obtained that applies to both normal and ultracold temperatures (1 mK). This expression assumes a canonical distribution of initial states, low-intensity excitation, and a semiclassical treatment of the survival probability relative to excited-state decay during the long time of the ultracold collision, and uses fine-structure-changing probabilities found by quantum scattering calculations. The known properties of the attractive molecular states of the alkaline-metal dimers are used to identify and calculate the probabilities for the specific mechanisms. We conclude that the earlier semiclassical analysis by Dashevskaya [Opt. Spectrosk. 46, 423 (1979)] of the fine-structure-changing mechanisms for the various alkali-metal species is qualitatively correct. We present quantum-mechanical calculations of the rate coefficient for fine-structure-changing collisions between ground- and excited-state Cs atoms from 1000 K to 100 \ensuremath{\mu}K. Collision-rate coefficients for the trap-loss processes are calculated for pairs of Li, Na, K, Rb, and Cs atoms at low temperature. There is a wide variation of predicted loss rate among alkali-metal species from the fastest for K and the slowest for Li. Retardation corrections to molecular lifetimes must be taken into account to predict the correct rate coefficients for Na, K, and Rb. Good agreement is obtained with the observed trap loss rate in a Cs trap.
Summary form only given. Inelastic collisions between cold atoms can lead to their ejection from the laser trap that confines them. Understanding these trap loss collisions is important to efforts aimed at high densities of cold atoms. Previously we have observed pronounced differences in the collisional behavior of the two isotopes, /sup 85/Rb and /sup 87/Rb, for the trap laser tuned one natural linewidth below resonance. We have extended our measurements for both isotopes to smaller and larger detunings in an effort to separate the various contributions to the trap loss rate.
We have previously reported experimental results on the trap-loss rate for a mixed species magneto-optical trap involving a pair of Na and Rb atoms [Phys. Rev. A 59, R23 (1999)]. The predicted dependence for the heteronuclear trap-loss rate as a function of laser detuning assuming a colliding pair of ground-state--excited-state atoms fails to explain the experimental results. Further investigation has shown that our observations are consistent if one assumes a loss channel involving an excited state--excited-state colliding pair of atoms. Here we present the model and discuss the physical interpretation applied to our previous experimental results. The present interpretation opens up other ways to understand the trap-loss mechanisms.