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

New Journal of Physics

Differential scattering measurements from a collider for ultracold atoms

Niels Kjærgaard, Angela S. Mellish, A. C. Wilson

Published Oct 28, 2004• 18 citations
Publisher

Abstract

We present a method for measuring differential cross sections from scattering halos produced by cold collisions between ultracold atomic clouds. Our scheme incorporates the dynamics of scattered particles within a harmonic potential that is used as a collider for the clouds. We demonstrate how to transform an experimentally acquired absorption image in order to obtain the angular scattering probability density.

DOI
10.1088/1367-2630/6/1/146

Related papers

BOSE-EINSTEIN CONDENSATES STUDIED WITH A LINEAR ACCELERATOR

Ch. Buggle, Jérémie Léonard, Wolf von Klitzing +1 more

We present a stand-alone interference method for the determination of the s- and d-wave scattering amplitudes in a quantum gas. Colliding two ultracold atomic clouds we observe the halo of scattered atoms in the rest frame of the collisional center of mass by absorption imaging. The clouds are accelerated up to energies at which the scattering pattern shows the interference between the s- (l = 0) and d- (l = 2) partial waves. With computerized tomography we transform the images to obtain the angular distribution, which is directly proportional to the difierential cross section. This allows us to measure the asymptotic phase shifts of the s- and d-wave scattering channels. The method does not require knowledge of the atomic density. It allows us to infer accurate values for the s- and dwave scattering amplitudes from the zero-energy limit up to the flrst RamsauerTownsend minimum using only the Van der Waals C6 coe‐cient as theoretical input. For the 87 Rb triplet potential, the method yields an accuracy of 6%.

Laser Spectroscopy•Dec 1, 2005•0 citations

Quantum scattering of distinguishable bosons using an ultracold-atom collider

Angela S. Mellish, Niels Kjærgaard, Paul S. Julienne +1 more

We describe an implementation of a magnetic collider for investigating cold collisions between ultracold atomic clouds in different spin states, and we use this to study scattering involving both even- and odd-order partial waves. Our method relies on the axial asymmetry of a double-well magnetic trap to selectively prepare the spin state in each cloud. We measure the energy dependence of $s$, $p$, and $d$ partial-wave phase shifts in collisions up to $300\phantom{\rule{0.3em}{0ex}}\ensuremath{\mu}\mathrm{K}$ between $^{87}\mathrm{Rb}$ atoms in the $5{S}_{1∕2},F=1,{m}_{F}=\ensuremath{-}1$ and $5{S}_{1∕2},F=2,{m}_{F}=1$ states.

arXiv:cond-mat/0610445•Physical Review A•Feb 16, 2007•13 citations

Testing quantum correlations in a confined atomic cloud by the scattering of fast atoms

Anatoly B. Kuklov, Boris V. Svistunov

We suggest measuring the one-particle density matrix of a trapped ultracold atomic cloud by the scattering of fast atoms in a pure momentum state off the cloud. The lowest-order probability for the process, resulting in a pair of outcoming fast atoms for each incoming one, as well as of its time-reversed counterpart, turns out to be given by the Fourier transform of the density matrix. Accordingly, important information about quantum correlations can be deduced directly from the differential scattering cross section of these processes. Several most interesting cases of scattering --- from a single condensate containing a vortex and from a split condensate characterized by some phase difference --- are discussed.

arXiv:cond-mat/9812016•Physical Review A•Aug 1, 1999•15 citations

Imaging of s and d Partial-Wave Interference in Quantum Scattering of Identical Bosonic Atoms

Nicholas R. Thomas, Niels Kjærgaard, Paul S. Julienne +1 more

We report on the direct imaging of s and d partial-wave interference in cold collisions of atoms. Two ultracold clouds of 87Rb atoms were accelerated by magnetic fields to collide at energies near a d-wave shape resonance. The resulting halos of scattered particles were imaged using laser absorption. By scanning across the resonance we observed a marked evolution of the scattering patterns due to the energy dependent phase shifts for the interfering s and d waves. Since only two partial-wave states are involved in the collision process the scattering yield and angular distributions have a simple interpretation in terms of a theoretical model.

arXiv:cond-mat/0405544•Physical Review Letters•Oct 22, 2004•100 citations

A laser based accelerator for ultracold atoms

We present first results on our implementation of a laser based accelerator for ultracold atoms. Atoms cooled to a temperature of 420 nK are confined and accelerated by means of laser tweezer beams and the atomic scattering is directly observed in laser absorption imaging. The optical collider has been characterized using 87Rb atoms in the |F = 2,mF = 2 〉 state, but the scheme is not restricted to atoms in any particular mag-netic substates and can readily be extended to other atomic species as well. c © 2012 Optical Society of America OCIS codes: 350.4855, 020.2070, 020.7010, 020.1475. The scattering experiment has been described as the most important experimental technique in quantum physics [1]. Typical textbook treatments describe the problem in terms of a beam impinging on a target: par-ticles collide along a well-defined axis with respect to which the angular scattering distribution of particles is determined. Knowledge about collision properties of neu-tral atoms at extremely low energies has been of crucial importance for developing the field of ultracold atomic

•Jan 1, 2012•0 citations

Testing quantum correlations in a confined atomic cloud by scattering fast atoms: Direct and time reversed processes

Anatoly B. Kuklov, Boris V. Svistunov

We suggest measuring the one-particle density matrix of a trapped ultracold atomic cloud by scattering fast atoms in a pure momentum state off the cloud. The lowest-order probability for the process, resulting in a pair of outcoming fast atoms for each incoming one, as well as of its time reversed counterpart, turns out to be given by the Fourier transform of the density matrix. Accordingly, important information about quantum correlations can be deduced directly from the differential scattering cross-section of these processes. Several most interesting cases of scattering - from a single condensate containing a vortex, and from a split condensate characterized by some phase difference - are discussed.

arXiv:cond-mat/9905426•May 29, 1999•0 citations
We present a method for measuring differential cross sections from scattering halos produced by cold collisions between ultracold atomic clouds. Our scheme incorporates the dynamics of scattered particles within a harmonic potential that is used as a collider for the clouds. We demonstrate how to transform an experimentally acquired absorption image in order to obtain the angular scattering probability density.
We present a stand-alone interference method for the determination of the s- and d-wave scattering amplitudes in a quantum gas. Colliding two ultracold atomic clouds we observe the halo of scattered atoms in the rest frame of the collisional center of mass by absorption imaging. The clouds are accelerated up to energies at which the scattering pattern shows the interference between the s- (l = 0) and d- (l = 2) partial waves. With computerized tomography we transform the images to obtain the angular distribution, which is directly proportional to the difierential cross section. This allows us to measure the asymptotic phase shifts of the s- and d-wave scattering channels. The method does not require knowledge of the atomic density. It allows us to infer accurate values for the s- and dwave scattering amplitudes from the zero-energy limit up to the flrst RamsauerTownsend minimum using only the Van der Waals C6 coe‐cient as theoretical input. For the 87 Rb triplet potential, the method yields an accuracy of 6%.
We describe an implementation of a magnetic collider for investigating cold collisions between ultracold atomic clouds in different spin states, and we use this to study scattering involving both even- and odd-order partial waves. Our method relies on the axial asymmetry of a double-well magnetic trap to selectively prepare the spin state in each cloud. We measure the energy dependence of sss, ppp, and ddd partial-wave phase shifts in collisions up to $300\phantom{\rule{0.3em}{0ex}}\ensuremath{\mu}\mathrm{K}$ between 87Rb^{87}\mathrm{Rb}87Rb atoms in the $5{S}_{1∕2},F=1,{m}_{F}=\ensuremath{-}1$ and 5S1∕2,F=2,mF=15{S}_{1∕2},F=2,{m}_{F}=15S1∕2​,F=2,mF​=1 states.
We suggest measuring the one-particle density matrix of a trapped ultracold atomic cloud by the scattering of fast atoms in a pure momentum state off the cloud. The lowest-order probability for the process, resulting in a pair of outcoming fast atoms for each incoming one, as well as of its time-reversed counterpart, turns out to be given by the Fourier transform of the density matrix. Accordingly, important information about quantum correlations can be deduced directly from the differential scattering cross section of these processes. Several most interesting cases of scattering --- from a single condensate containing a vortex and from a split condensate characterized by some phase difference --- are discussed.
We report on the direct imaging of s and d partial-wave interference in cold collisions of atoms. Two ultracold clouds of 87Rb atoms were accelerated by magnetic fields to collide at energies near a d-wave shape resonance. The resulting halos of scattered particles were imaged using laser absorption. By scanning across the resonance we observed a marked evolution of the scattering patterns due to the energy dependent phase shifts for the interfering s and d waves. Since only two partial-wave states are involved in the collision process the scattering yield and angular distributions have a simple interpretation in terms of a theoretical model.
We present first results on our implementation of a laser based accelerator for ultracold atoms. Atoms cooled to a temperature of 420 nK are confined and accelerated by means of laser tweezer beams and the atomic scattering is directly observed in laser absorption imaging. The optical collider has been characterized using 87Rb atoms in the |F = 2,mF = 2 〉 state, but the scheme is not restricted to atoms in any particular mag-netic substates and can readily be extended to other atomic species as well. c © 2012 Optical Society of America OCIS codes: 350.4855, 020.2070, 020.7010, 020.1475. The scattering experiment has been described as the most important experimental technique in quantum physics [1]. Typical textbook treatments describe the problem in terms of a beam impinging on a target: par-ticles collide along a well-defined axis with respect to which the angular scattering distribution of particles is determined. Knowledge about collision properties of neu-tral atoms at extremely low energies has been of crucial importance for developing the field of ultracold atomic
We suggest measuring the one-particle density matrix of a trapped ultracold atomic cloud by scattering fast atoms in a pure momentum state off the cloud. The lowest-order probability for the process, resulting in a pair of outcoming fast atoms for each incoming one, as well as of its time reversed counterpart, turns out to be given by the Fourier transform of the density matrix. Accordingly, important information about quantum correlations can be deduced directly from the differential scattering cross-section of these processes. Several most interesting cases of scattering - from a single condensate containing a vortex, and from a split condensate characterized by some phase difference - are discussed.