Vortex shedding and drag in dilute Bose-Einstein condensates

T. Winiecki, Jackson, B., McCann, Jim, Charles S. Adams

Published Oct 14, 2000• 47 citations

Abstract

Above a critical velocity, the dominant mechanism of energy transfer between a moving object and a dilute Bose-Einstein condensate is vortex formation. In this paper, we discuss the critical velocity for vortex formation and the link between vortex shedding and drag in both homogeneous and inhomogeneous condensates. We find that at supersonic velocities sound radiation also contributes significantly to the drag force.

Related papers

Vortex shedding and drag in dilute Bose-Einstein condensates

T Winiecki, B Jackson, J F McCann +1 more

arXiv:cond-mat/0004430Journal of Physics B Atomic Molecular and Optical PhysicsSep 15, 200083 citations

Dissipative Flow and Vortex Shedding in the Painlevé Boundary Layer of a Bose-Einstein Condensate

Amandine Aftalion, Qiang Du, Yves Pomeau A

arXiv:cond-mat/0303096Physical Review LettersAug 28, 200347 citations

Superfluid critical velocity in dilute gas Bose-Einstein condensates

Chao Feng

May 25, 20200 citations

Vortex Formation in Dilute Inhomogeneous Bose-Einstein Condensates

Brian K. Jackson, J F McCann, Charles S. Adams

We solve the time-dependent Gross-Pitaevskii in 2D to simulate the flow of an object through a dilute Bose-Einstein condensate trapped in a harmonic well. We demonstrate vortex formation and study the process in terms of the accumulation of phase slip and the evolution of the fluid velocity.

Physical Review LettersMay 4, 1998167 citations

Structure of vortex shedding past potential barriers moving in a Bose-Einstein condensate

V. A. Mironov, A. I. Smirnov, Lev A. Smirnov

The problem of excitation of a homogeneous Bose-Einstein condensate by axially symmetric potential barriers moving with respect to the condensate with both supersonic and subsonic velocities is considered in terms of the Gross-Pitaevskii equation. The specific features of the structure of the vortex shedding past the barriers are analyzed for both regimes of motion.

Journal of Experimental and Theoretical PhysicsMay 1, 201038 citations

Critical velocity for vortex shedding in a Bose-Einstein condensate

Woo Jin Kwon, Geol Moon, Sang Won Seo +1 more

arXiv:1502.03542Physical Review AMay 15, 201580 citations

Vortex shedding and drag in dilute Bose-Einstein condensates

T. Winiecki, Jackson, B., McCann, Jim, Charles S. Adams

Published Oct 14, 2000• 47 citations

OpenAlex

Abstract

Related papers

Vortex shedding and drag in dilute Bose-Einstein condensates

T Winiecki, B Jackson, J F McCann +1 more

arXiv:cond-mat/0004430Journal of Physics B Atomic Molecular and Optical PhysicsSep 15, 200083 citations

Dissipative Flow and Vortex Shedding in the Painlevé Boundary Layer of a Bose-Einstein Condensate

Amandine Aftalion, Qiang Du, Yves Pomeau A

This paper addresses the drag force and formation of vortices in the boundary layer of a Bose-Einstein condensate stirred by a laser beam following the experiments of Phys. Rev. Lett. 83, 2502 (1999)]. We make our analysis in the frame moving at constant speed where the beam is fixed. We find that there is always a drag around the laser beam. We also analyze the mechanism of vortex nucleation. At low velocity, there are no vortices and the drag has its origin in a wakelike phenomenon: This is a particularity of trapped systems since the density gets small in an extended region. The shedding of vortices starts only at a threshold velocity and is responsible for a large increase in drag. This critical velocity for vortex nucleation is lower than the critical velocity computed for the corresponding 2D problem at the center of the cloud.This paper addresses the drag force and formation of vortices in the boundary layer of a Bose-Einstein condensate stirred by a laser beam following the experiments of Phys. Rev. Lett. 83, 2502 (1999)]. We make our analysis in the frame moving at constant speed where the beam is fixed. We find that there is always a drag around the laser beam. We also analyze the mechanism of vortex nucleation. At low velocity, there are no vortices and the drag has its origin in a wakelike phenomenon: This is a particularity of trapped systems since the density gets small in an extended region. The shedding of vortices starts only at a threshold velocity and is responsible for a large increase in drag. This critical velocity for vortex nucleation is lower than the critical velocity computed for the corresponding 2D problem at the center of the cloud.

arXiv:cond-mat/0303096Physical Review LettersAug 28, 200347 citations

Superfluid critical velocity in dilute gas Bose-Einstein condensates

Chao Feng

This thesis examines the manifestation of the critical velocity for superfluidity in dilute gas Bose-Einstein condensates (BECs). Superfluidity is a macroscopic quantum phenomenon characterised by unique properties such as frictionless flow, high thermal conductivity and the presence of quantised vortices. Our study focuses on what is arguably the most well-known attribute: the ability for an object to move through a superfluid without experiencing a drag force when travelling below a threshold critical velocity.The Landau criterion for superfluidity predicts the critical velocity in a BEC is equal to the speed of sound, and this conclusion is supported by a large body of theoretical work. However, a number of experiments have observed lower critical velocities than theory predicts. In the first part of this thesis, we numerically model experiments on the superfluid critical velocity of an elongated, harmonically trapped Bose-Einstein condensate as reported by [P. Engels and C. Atherton, Phys. Rev. Lett. 99, 160405 (2007)]. These experiments swept a repulsive obstacle, formed by a optical dipole potential, through the long axis of a condensate at constant velocity. Their results found an increase in the resulting density fluctuations of the condensate above an obstacle velocity of v _ 0:3 mm sThis thesis examines the manifestation of the critical velocity for superfluidity in dilute gas Bose-Einstein condensates (BECs). Superfluidity is a macroscopic quantum phenomenon characterised by unique properties such as frictionless flow, high thermal conductivity and the presence of quantised vortices. Our study focuses on what is arguably the most well-known attribute: the ability for an object to move through a superfluid without experiencing a drag force when travelling below a threshold critical velocity.The Landau criterion for superfluidity predicts the critical velocity in a BEC is equal to the speed of sound, and this conclusion is supported by a large body of theoretical work. However, a number of experiments have observed lower critical velocities than theory predicts. In the first part of this thesis, we numerically model experiments on the superfluid critical velocity of an elongated, harmonically trapped Bose-Einstein condensate as reported by [P. Engels and C. Atherton, Phys. Rev. Lett. 99, 160405 (2007)]. These experiments swept a repulsive obstacle, formed by a optical dipole potential, through the long axis of a condensate at constant velocity. Their results found an increase in the resulting density fluctuations of the condensate above an obstacle velocity of v _ 0:3 mm s

May 25, 20200 citations

Vortex Formation in Dilute Inhomogeneous Bose-Einstein Condensates

Brian K. Jackson, J F McCann, Charles S. Adams

Physical Review LettersMay 4, 1998167 citations

Structure of vortex shedding past potential barriers moving in a Bose-Einstein condensate

V. A. Mironov, A. I. Smirnov, Lev A. Smirnov

Journal of Experimental and Theoretical PhysicsMay 1, 201038 citations

Critical velocity for vortex shedding in a Bose-Einstein condensate

Woo Jin Kwon, Geol Moon, Sang Won Seo +1 more

We present measurements of the critical velocity for vortex shedding in a highly oblate Bose-Einstein condensate with a moving repulsive Gaussian laser beam. As a function of the barrier height ${V}_{0}$ , the critical velocity ${v}_{c}$ shows a dip structure having a minimum at ${V}_{0}\ensuremath{\approx}\ensuremath{\mu}$, where $\ensuremath{\mu}$ is the chemical potential of the condensate. At fixed ${V}_{0}\ensuremath{\approx}7\ensuremath{\mu}$, we observe that the ratio of ${v}_{c}$ to the speed of sound ${c}_{s}$ monotonically increases for decreasing $\ensuremath{\sigma}/\ensuremath{\xi}$, where $\ensuremath{\sigma}$ is the beam width and $\ensuremath{\xi}$ is the condensate healing length. We explain our results with the density reduction effect of the soft boundary of the Gaussian obstacle, based on the local Landau criterion for superfluidity. The measured value of ${v}_{c}/{c}_{s}$ with our stiffest obstacle is about 0.4, which is in good agreement with theoretical predictions for a two-dimensional superflow past a circular cylinder.We present measurements of the critical velocity for vortex shedding in a highly oblate Bose-Einstein condensate with a moving repulsive Gaussian laser beam. As a function of the barrier height ${V}_{0}$, the critical velocity ${v}_{c}$ shows a dip structure having a minimum at ${V}_{0}\ensuremath{\approx}\ensuremath{\mu}$, where $\ensuremath{\mu}$ is the chemical potential of the condensate. At fixed ${V}_{0}\ensuremath{\approx}7\ensuremath{\mu}$, we observe that the ratio of ${v}_{c}$ to the speed of sound ${c}_{s}$ monotonically increases for decreasing $\ensuremath{\sigma}/\ensuremath{\xi}$, where $\ensuremath{\sigma}$ is the beam width and $\ensuremath{\xi}$ is the condensate healing length. We explain our results with the density reduction effect of the soft boundary of the Gaussian obstacle, based on the local Landau criterion for superfluidity. The measured value of ${v}_{c}/{c}_{s}$ with our stiffest obstacle is about 0.4, which is in good agreement with theoretical predictions for a two-dimensional superflow past a circular cylinder.

arXiv:1502.03542Physical Review AMay 15, 201580 citations

We present measurements of the critical velocity for vortex shedding in a highly oblate Bose-Einstein condensate with a moving repulsive Gaussian laser beam. As a function of the barrier height

{V}_{0}

, the critical velocity

{v}_{c}

shows a dip structure having a minimum at ${V}_{0}\ensuremath{\approx}\ensuremath{\mu}$, where $\ensuremath{\mu}$ is the chemical potential of the condensate. At fixed ${V}_{0}\ensuremath{\approx}7\ensuremath{\mu}$, we observe that the ratio of

{v}_{c}

to the speed of sound

{c}_{s}

monotonically increases for decreasing $\ensuremath{\sigma}/\ensuremath{\xi}$, where $\ensuremath{\sigma}$ is the beam width and $\ensuremath{\xi}$ is the condensate healing length. We explain our results with the density reduction effect of the soft boundary of the Gaussian obstacle, based on the local Landau criterion for superfluidity. The measured value of

{v}_{c}/{c}_{s}

with our stiffest obstacle is about 0.4, which is in good agreement with theoretical predictions for a two-dimensional superflow past a circular cylinder.