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

Bose Beams: Coherent Propagation Through a Guide

P. Lebœuf, Nicolas Pavloff

Published Jan 1, 2001• 0 citations
OpenAlex

Abstract

We compute the stationary profiles of a coherent beam of Bose condensed atoms propagating through a guide. Special emphasis is put on the effect of an obstacle present on the trajectory of the beam. The obstacle considered (such as a bend in the guide, or a laser field perpendicular to the beam) results in a repulsive or an attractive potential acting on the condensate. Different behaviors are observed when varying the beam velocity (with respect to the speed of sound), the size of the obstacle (relative to the healing length) and the intensity and sign of the potential. The existence of bound states of the condensate is also considered. PACS numbers: 03.75.b Matter waves 03.75.Fi Phase coherent atomic ensembles; quantum condensation phenomena 42.65.Tg Optical solitons; nonlinear guided waves 67.60.Hf Hydrodynamics in specific geometries, flow in narrow channels 1 Unité Mixte de Recherche de l’Université Paris XI et du CNRS (UMR 8626).

Related papers

Bose-Einstein beams: Coherent propagation through a guide

P. Lebœuf, Nicolas Pavloff

We compute the stationary profiles of a coherent beam of Bose-Einstein-condensed atoms propagating through a guide. Special emphasis is put on the effect of a disturbing obstacle present in the trajectory of the beam. The obstacle considered (such as a bend in the guide, or a laser field perpendicular to the beam) results in a repulsive or an attractive potential acting on the condensate. Different behaviors are observed when the beam velocity (with respect to the speed of sound), the size of the obstacle (relative to the healing length), and the intensity and sign of the potential are varied. The existence of bound states of the condensate is also considered.

arXiv:cond-mat/0103294•Physical Review A•Aug 3, 2001•153 citations

Soliton dynamics in the collisions of Bose - Einstein condensates: an analogue of the Josephson effect

William P. Reinhardt, Charles W. Clark

The usual mean-field description of trapped atomic Bose - Einstein condensates predicts the existence of solitons in one-dimensional and quasi-one-dimensional confinement. If the net atomic pair interaction is attractive, these solitons appear as coherently propagating matter wavepackets; if it is repulsive, soliton behaviour is seen in the motion of `holes' in the condensate density, the velocity of which is determined by the phase difference between adjoining pieces of condensate, in analogy to the familiar Josephson effect. We explore the properties of these solitons via elementary analytic models and computer simulation, and make specific suggestions for their experimental observation.

Journal of Physics B Atomic Molecular and Optical Physics•Nov 28, 1997•173 citations

Breakdown of superfluidity of an atom laser past an obstacle

Nicolas Pavloff

The one-dimensional flow of a continuous beam of Bose-Einstein condensed atoms in the presence of an obstacle is studied as a function of the beam velocity and of the type of perturbing potential (representing the interaction of the obstacle with the atoms of the beam). We identify the relevant regimes: stationary/time-dependent and superfluid/dissipative; the absence of drag is used as a criterion for superfluidity. There exists a critical velocity below which the flow is superfluid. For attractive obstacles, we show that this critical velocity can reach the value predicted by Landau's approach. Besides, for penetrable obstacles, it is shown that superfluidity is recovered at large beam velocity. Finally, enormous differences in drag occur when switching from repulsive to attractive potential.

arXiv:cond-mat/0206271•Physical Review A•Jul 19, 2002•123 citations

Manipulation and phase engineering of Bose-Einstein condensates

Kai Bongs

We present experiments investigating different aspects concerning the coherent manipulation of a Bose-Einstein condensate wavefunction with far blue detuned dipole potentials. In a first set of experiments we study a waveguide for matter waves as an important atom optical element allowing to hold and guide the atoms for long observation times. We present a flexible realization of this waveguide based on a tube shaped Laguerre Gaussian laser beam and investigate the dynamics of a Bose condensed ensemble transferred into this guide. In a second set of experiments we study the dynamics of dark solitons created by the manipulation of the phase of the condensate wave function by temporally applied dipole potentials. This method of phase imprinting represents a powerful tool for the design of matter waves and the controlled creation of various excitations. The dynamics of dark solitons in matter waves is investigated in detail by experimentally and numerically studying the temporal evolution of the condensate density as well as by mapping the velocity field of the excited condensate wavefunction. In these measurements we directly detect the flux of the wave function associated with the dark soliton using spatially resolved Bragg scattering. Experiments investigating the creation and interaction of several dark solitons conclude this chapter.

AIP conference proceedings•Jan 1, 2001•0 citations

Bright matter wave solitons in Bose–Einstein condensates

Kevin E. Strecker, Guthrie B. Partridge, Andrew G. Truscott +1 more

We review recent experimental and theoretical work on the creation of bright matter wave solitons in Bose–Einstein condensates. In two recent experiments, solitons are formed from Bose–Einstein condensates of 7 Li by utilizing a Feshbach resonance to switch from repulsive to attractive interactions. The solitons are made to propagate in a one-dimensional potential formed by a focused laser beam. For repulsive interactions, the wavepacket undergoes dispersive wavepacket spreading, while for attractive interactions, localized solitons are formed. In our experiment, a multi-soliton train containing up to ten solitons is observed to propagate without spreading for a duration of 2 s. Adjacent solitons are found to interact repulsively, in agreement with a calculation based on the nonlinear Schrödinger equation assuming that the soliton train is formed with an alternating phase structure. The origin of this phase structure is not entirely clear.

New Journal of Physics•Jun 16, 2003•213 citations

Nonlinear transport of Bose-Einstein condensates through waveguides with disorder

Tobias Paul, P. Lebœuf, Nicolas Pavloff +2 more

We study the coherent flow of a guided Bose-Einstein condensate incident over a disordered region of length $L$. We introduce a model of disordered potential that originates from magnetic fluctuations inherent to microfabricated guides. This model allows for analytical and numerical studies of realistic transport experiments. The repulsive interaction among the condensate atoms in the beam induces different transport regimes. Below some critical interaction (or for sufficiently small $L$) a stationary flow is observed. In this regime, the transmission decreases exponentially with increasing $L$. For strong interaction (or large $L$), the system displays a transition toward a time-dependent flow with an algebraic decay of the time-averaged transmission.

arXiv:cond-mat/0509446•Physical Review A•Dec 28, 2005•79 citations
We compute the stationary profiles of a coherent beam of Bose condensed atoms propagating through a guide. Special emphasis is put on the effect of an obstacle present on the trajectory of the beam. The obstacle considered (such as a bend in the guide, or a laser field perpendicular to the beam) results in a repulsive or an attractive potential acting on the condensate. Different behaviors are observed when varying the beam velocity (with respect to the speed of sound), the size of the obstacle (relative to the healing length) and the intensity and sign of the potential. The existence of bound states of the condensate is also considered. PACS numbers: 03.75.b Matter waves 03.75.Fi Phase coherent atomic ensembles; quantum condensation phenomena 42.65.Tg Optical solitons; nonlinear guided waves 67.60.Hf Hydrodynamics in specific geometries, flow in narrow channels 1 Unité Mixte de Recherche de l’Université Paris XI et du CNRS (UMR 8626).
We compute the stationary profiles of a coherent beam of Bose-Einstein-condensed atoms propagating through a guide. Special emphasis is put on the effect of a disturbing obstacle present in the trajectory of the beam. The obstacle considered (such as a bend in the guide, or a laser field perpendicular to the beam) results in a repulsive or an attractive potential acting on the condensate. Different behaviors are observed when the beam velocity (with respect to the speed of sound), the size of the obstacle (relative to the healing length), and the intensity and sign of the potential are varied. The existence of bound states of the condensate is also considered.
The usual mean-field description of trapped atomic Bose - Einstein condensates predicts the existence of solitons in one-dimensional and quasi-one-dimensional confinement. If the net atomic pair interaction is attractive, these solitons appear as coherently propagating matter wavepackets; if it is repulsive, soliton behaviour is seen in the motion of `holes' in the condensate density, the velocity of which is determined by the phase difference between adjoining pieces of condensate, in analogy to the familiar Josephson effect. We explore the properties of these solitons via elementary analytic models and computer simulation, and make specific suggestions for their experimental observation.
The one-dimensional flow of a continuous beam of Bose-Einstein condensed atoms in the presence of an obstacle is studied as a function of the beam velocity and of the type of perturbing potential (representing the interaction of the obstacle with the atoms of the beam). We identify the relevant regimes: stationary/time-dependent and superfluid/dissipative; the absence of drag is used as a criterion for superfluidity. There exists a critical velocity below which the flow is superfluid. For attractive obstacles, we show that this critical velocity can reach the value predicted by Landau's approach. Besides, for penetrable obstacles, it is shown that superfluidity is recovered at large beam velocity. Finally, enormous differences in drag occur when switching from repulsive to attractive potential.
We present experiments investigating different aspects concerning the coherent manipulation of a Bose-Einstein condensate wavefunction with far blue detuned dipole potentials. In a first set of experiments we study a waveguide for matter waves as an important atom optical element allowing to hold and guide the atoms for long observation times. We present a flexible realization of this waveguide based on a tube shaped Laguerre Gaussian laser beam and investigate the dynamics of a Bose condensed ensemble transferred into this guide. In a second set of experiments we study the dynamics of dark solitons created by the manipulation of the phase of the condensate wave function by temporally applied dipole potentials. This method of phase imprinting represents a powerful tool for the design of matter waves and the controlled creation of various excitations. The dynamics of dark solitons in matter waves is investigated in detail by experimentally and numerically studying the temporal evolution of the condensate density as well as by mapping the velocity field of the excited condensate wavefunction. In these measurements we directly detect the flux of the wave function associated with the dark soliton using spatially resolved Bragg scattering. Experiments investigating the creation and interaction of several dark solitons conclude this chapter.
We review recent experimental and theoretical work on the creation of bright matter wave solitons in Bose–Einstein condensates. In two recent experiments, solitons are formed from Bose–Einstein condensates of 7 Li by utilizing a Feshbach resonance to switch from repulsive to attractive interactions. The solitons are made to propagate in a one-dimensional potential formed by a focused laser beam. For repulsive interactions, the wavepacket undergoes dispersive wavepacket spreading, while for attractive interactions, localized solitons are formed. In our experiment, a multi-soliton train containing up to ten solitons is observed to propagate without spreading for a duration of 2 s. Adjacent solitons are found to interact repulsively, in agreement with a calculation based on the nonlinear Schrödinger equation assuming that the soliton train is formed with an alternating phase structure. The origin of this phase structure is not entirely clear.
We study the coherent flow of a guided Bose-Einstein condensate incident over a disordered region of length LLL. We introduce a model of disordered potential that originates from magnetic fluctuations inherent to microfabricated guides. This model allows for analytical and numerical studies of realistic transport experiments. The repulsive interaction among the condensate atoms in the beam induces different transport regimes. Below some critical interaction (or for sufficiently small LLL) a stationary flow is observed. In this regime, the transmission decreases exponentially with increasing LLL. For strong interaction (or large LLL), the system displays a transition toward a time-dependent flow with an algebraic decay of the time-averaged transmission.