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

arXiv:1112.4754 · Physical Review A

Nonexponential one-body loss in a Bose-Einstein condensate

Steven Knoop, Joseph Steven Borbely, Rob van Rooij, W. Vassen

Published Feb 14, 2012• 9 citations
arXivHTMLPDF

Abstract

We have studied the decay of a Bose-Einstein condensate (BEC) of metastable helium atoms in an optical dipole trap. In the regime where two- and three-body losses can be neglected we show that the Bose-Einstein condensate and the thermal cloud show fundamentally different decay characteristics. The total number of atoms decays exponentially with time constant $\ensuremath{\tau}$; however, the thermal cloud decays exponentially with time constant $\frac{4}{3}\ensuremath{\tau}$ and the condensate decays much faster, and nonexponentially. We show that this behavior, which should be present for all BECs in thermal equilibrium with a considerable thermal fraction, is due to a transfer of atoms from the condensate to the thermal cloud during its decay.

DOI
10.1103/physreva.85.025602

Related papers

Magnetic-field-dependent trap loss of ultracold metastable helium

Joseph Steven Borbely, Rob van Rooij, Steven Knoop +1 more

We have experimentally studied the magnetic-field dependence of the decay of a Bose-Einstein condensate of metastable ${}^{4}$He atoms confined in an optical dipole trap, for atoms in the $m=+1$ and $m=\ensuremath{-}1$ magnetic substates, and up to 450 G. Our measurements confirm longstanding calculations of the two-body loss rate coefficient that show an increase above 50 G. We demonstrate that for $m=\ensuremath{-}1$ atoms decay is due to three-body recombination only, with a three-body loss rate coefficient of $6.5{(0.4)}_{\mathrm{stat}}{(0.6)}_{\mathrm{sys}}\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}27}$ cm${}^{6}$s${}^{\ensuremath{-}1}$, which is interesting in the context of universal few-body theory. We have also searched for a recently predicted $d$-wave Feshbach resonance, but did not observe it.

arXiv:1111.5829•Physical Review A•Feb 14, 2012•16 citations

Using ion production to monitor the birth and death of a metastable helium Bose Einstein condensate

Signe Louise Seidelin, O. Sirjean, José Viana‐Gomes +3 more

We discuss observations of the ion flux from a cloud of trapped 2 3 S 1 metastable helium atoms. Both Bose–Einstein condensates (BEC) and thermal clouds were investigated. The ion flux is compared with time-of-flight observations of the expanded cloud. We show data concerning BEC formation and decay, as well as measurements of two-and three-body ionization rate constants. We also discuss possible improvements and extensions of our results.

arXiv:cond-mat/0211112•Journal of Optics B Quantum and Semiclassical Optics•Apr 1, 2003•15 citations

The effect of atomic transfer on the decay of a Bose Einstein condensate

P. F. Zi, Andrzej Dragan, Szymon Charzyński +4 more

We present a model describing the decay of a Bose-Einstein condensate, which assumes the system to remain in thermal equilibrium during the decay. We show that under this assumption transfer of atoms occurs from the condensate to the thermal cloud enhancing the condensate decay rate.

arXiv:quant-ph/0303134•Journal of Physics B Atomic Molecular and Optical Physics•Mar 27, 2003•5 citations

Bose-Einstein Condensation of Metastable Helium

Franck Pereira dos Santos, Jérémie Léonard, Junmin Wang +6 more

We have observed a Bose-Einstein condensate in a dilute gas of ${}^{4}\mathrm{He}$ in the $^{3}2S_{1}$ metastable state. We find a critical temperature of $(4.7\ifmmode\pm\else\textpm\fi{}0.5)\ensuremath{\mu}\mathrm{K}$ and a typical number of atoms at the threshold of $8\ifmmode\times\else\texttimes\fi{}{10}^{6}$. The maximum number of atoms in our condensate is about $5\ifmmode\times\else\texttimes\fi{}{10}^{5}$. An approximate value for the scattering length $a\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}(16\ifmmode\pm\else\textpm\fi{}8)\mathrm{nm}$ is measured. The mean elastic collision rate at threshold is then estimated to be about $2\ifmmode\times\else\texttimes\fi{}{10}^{4}{\mathrm{s}}^{\ensuremath{-}1}$, indicating that we are deeply in the hydrodynamic regime. The typical decay time of the condensate is $2\mathrm{s}$, which places an upper bound on the rate constants for two-body and three-body inelastic collisions.

arXiv:cond-mat/0103387•Physical Review Letters•Apr 16, 2001•313 citations

Optical Confinement of a Bose-Einstein Condensate

Dan Stamper-Kurn, Michael R. Andrews, A. P. Chikkatur +4 more

Bose-Einstein condensates of sodium atoms have been confined in an optical dipole trap using a single focused infrared laser beam. This eliminates the restrictions of magnetic traps for further studies of atom lasers and Bose-Einstein condensates. More than $5\ifmmode\times\else\texttimes\fi{}{10}^{6}$ condensed atoms were transferred into the optical trap. Densities of up to $3\ifmmode\times\else\texttimes\fi{}{10}^{15}{\mathrm{cm}}^{\ensuremath{-}3}$ of Bose condensed atoms were obtained, allowing for a measurement of the three-body loss rate constant for sodium condensates as ${K}_{3}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}1.1(3)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}30}{\mathrm{cm}}^{6}{\mathrm{s}}^{\ensuremath{-}1}$. At lower densities, the observed $1/e$ lifetime was longer than 10 s. Simultaneous confinement of Bose-Einstein condensates in several hyperfine states was demonstrated.

arXiv:cond-mat/9711273•Physical Review Letters•Mar 9, 1998•1,068 citations

Ionization Rates in a Bose-Einstein Condensate of Metastable Helium

O. Sirjean, Signe Louise Seidelin, José Viana‐Gomes +4 more

We have studied ionizing collisions in a BEC of metastable He. Measurements of the ion production rate combined with measurements of the density and number of atoms for the same sample allow us to estimate both the two- and three-body contributions to this rate. A comparison with the decay of the atom number indicates that ionizing collisions are largely or wholly responsible for the loss. Quantum depletion makes a substantial correction to the three-body rate constant.

arXiv:cond-mat/0208108•Physical Review Letters•Nov 12, 2002•26 citations
We have studied the decay of a Bose-Einstein condensate (BEC) of metastable helium atoms in an optical dipole trap. In the regime where two- and three-body losses can be neglected we show that the Bose-Einstein condensate and the thermal cloud show fundamentally different decay characteristics. The total number of atoms decays exponentially with time constant \ensuremathτ\ensuremath{\tau}\ensuremathτ; however, the thermal cloud decays exponentially with time constant 43\ensuremathτ\frac{4}{3}\ensuremath{\tau}34​\ensuremathτ and the condensate decays much faster, and nonexponentially. We show that this behavior, which should be present for all BECs in thermal equilibrium with a considerable thermal fraction, is due to a transfer of atoms from the condensate to the thermal cloud during its decay.
We have experimentally studied the magnetic-field dependence of the decay of a Bose-Einstein condensate of metastable 4{}^{4}4He atoms confined in an optical dipole trap, for atoms in the m=+1m=+1m=+1 and $m=\ensuremath{-}1$ magnetic substates, and up to 450 G. Our measurements confirm longstanding calculations of the two-body loss rate coefficient that show an increase above 50 G. We demonstrate that for $m=\ensuremath{-}1$ atoms decay is due to three-body recombination only, with a three-body loss rate coefficient of $6.5{(0.4)}_{\mathrm{stat}}{(0.6)}_{\mathrm{sys}}\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}27}$ cm6{}^{6}6s${}^{\ensuremath{-}1}$, which is interesting in the context of universal few-body theory. We have also searched for a recently predicted ddd-wave Feshbach resonance, but did not observe it.
We have observed a Bose-Einstein condensate in a dilute gas of 4He{}^{4}\mathrm{He}4He in the 32S1^{3}2S_{1}32S1​ metastable state. We find a critical temperature of $(4.7\ifmmode\pm\else\textpm\fi{}0.5)\ensuremath{\mu}\mathrm{K}$ and a typical number of atoms at the threshold of $8\ifmmode\times\else\texttimes\fi{}{10}^{6}$. The maximum number of atoms in our condensate is about $5\ifmmode\times\else\texttimes\fi{}{10}^{5}$. An approximate value for the scattering length $a\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}(16\ifmmode\pm\else\textpm\fi{}8)\mathrm{nm}$ is measured. The mean elastic collision rate at threshold is then estimated to be about $2\ifmmode\times\else\texttimes\fi{}{10}^{4}{\mathrm{s}}^{\ensuremath{-}1}$, indicating that we are deeply in the hydrodynamic regime. The typical decay time of the condensate is 2s2\mathrm{s}2s, which places an upper bound on the rate constants for two-body and three-body inelastic collisions.
Bose-Einstein condensates of sodium atoms have been confined in an optical dipole trap using a single focused infrared laser beam. This eliminates the restrictions of magnetic traps for further studies of atom lasers and Bose-Einstein condensates. More than $5\ifmmode\times\else\texttimes\fi{}{10}^{6}$ condensed atoms were transferred into the optical trap. Densities of up to $3\ifmmode\times\else\texttimes\fi{}{10}^{15}{\mathrm{cm}}^{\ensuremath{-}3}$ of Bose condensed atoms were obtained, allowing for a measurement of the three-body loss rate constant for sodium condensates as ${K}_{3}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}1.1(3)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}30}{\mathrm{cm}}^{6}{\mathrm{s}}^{\ensuremath{-}1}$. At lower densities, the observed 1/e1/e1/e lifetime was longer than 10 s. Simultaneous confinement of Bose-Einstein condensates in several hyperfine states was demonstrated.