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:cond-mat/9908470 · Physical Review A

Creation of a persistent current and vortex in a Bose-Einstein condensate of alkali-metal atoms

Tomoya Isoshima, Mikio Nakahara, Tetsuo Ohmi, Kazushige Machida

Published May 16, 2000• 176 citations
arXivHTMLPDF

Abstract

It is shown theoretically that a persistent current can be continuously created in a Bose-Einstein condensate (BEC) of alkali-metal atoms confined in a multiply connected region by making use of a spin degree of freedom of the order parameter of a BEC. We demonstrate that this persistent current is easily transformed into a vortex. Relaxation processes of these BEC after the confining field is turned off are also studied, so that our analyses are compared with time-of-flight experiments. The results are shown to clearly reflect the existence of a persistent current.

DOI
10.1103/physreva.61.063610

Related papers

Vortex stabilization in Bose-Einstein condensate of alkali-metal atom gas

Tomoya Isoshima, Kazushige Machida

A quantized vortex in Bose-Einstein condensation (BEC) of an alkali-metal atom gas is known to be unstable intrinsically at zero temperature. We examine two stabilization mechanisms of a vortex theoretically. (i) The finite temperature effect is shown to stabilize a vortex. (ii) An additional pinning potential, which may be produced by a focused laser beam at the vortex center, is also shown to stabilize it even at zero temperature. The mean-field calculation for BEC confined by a harmonic potential is employed. The detailed properties of a stable vortex are given, such as the spatial profiles of the condensate and noncondensate, the particle current density around the core, the whole excitation spectrum, and their temperature dependence.

arXiv:cond-mat/9807250•Physical Review A•Mar 1, 1999•68 citations

Vortices and Persistent Currents: Rotating a Bose-Einstein Condensate Using Photons with Orbital Angular Momentum

Kristian Helmerson, Mikkel F. Andersen, Pierre Cladé +5 more

We describe the coherent transfer of the orbital angular momentum of a photon to an atom in quantized units of ℏ, using a 2-photon stimulated Raman process with Laguerre-Gaussian beams to generate an atomic vortex state in a Bose-Einstein condensate (BEC) of sodium atoms. We show that the process is coherent by creating superpositions of different vortex states, where the relative phase between the states is determined by the relative phases of the optical fields. We use this technique to generate circular flow of a BEC confined in a toriodal shaped trap. We measure that the flow of atoms persists for up to 10 seconds, which we interpret as the first evidence of persistent currents in a superfluid Bose gas.

Topologica•Jan 1, 2009•6 citations

Continuous Creation of a Vortex in a Bose-Einstein Condensate with Hyperfine Spin F=2

Mikko Möttönen, Naoki Matsumoto, Mikio Nakahara +1 more

It is shown that a vortex can be continuously created in a Bose-Einstein condensate with hyperfine spin F=2 in a Ioffe-Pritchard trap by reversing the axial magnetic field adiabatically. It may be speculated that the condensate cannot be confined in the trap since the weak-field seeking state makes transitions to the neutral and the strong-field seeking states due to the degeneracy of these states along the vortex axis when the axial field vanishes. We have solved the Gross-Pitaevskii equation numerically with given external magnetic fields to show that this is not the case. It is shown that a considerable fraction of the condensate remains in the trap even when the axial field is reversed rather slowly. This scenario is also analysed in the presence of an optical plug along the vortex axis. Then the condensate remains within the $F_z=2$ manifold, with respect to the local magnetic field, throughout the formation of a vortex and hence the loss of atoms does not take place.

arXiv:cond-mat/0205542•May 27, 2002•1 citation

Continuous creation of a vortex in a Bose Einstein condensate with hyperfine spinF 2

Mikko Möttönen, Naoki Matsumoto, Mikio Nakahara +1 more

It is shown that a vortex can be continuously created in a Bose–Einstein condensate with hyperfine spin F = 2 in a Ioffe–Pritchard trap by reversing the axial magnetic field adiabatically. It may be speculated that the condensate cannot be confined in the trap since the weak-field seeking state makes transitions to the neutral and the strong-field seeking states due to the degeneracy of these states along the vortex axis when the axial field vanishes. We have solved the Gross–Pitaevskii equation numerically with given external magnetic fields to show that this is not the case. It is shown that a considerable fraction of the condensate remains in the trap even when the axial field is reversed rather slowly. This scenario is also analysed in the presence of an optical plug along the vortex axis. Then the condensate remains within the F z = 2 manifold, with respect to the local magnetic field, throughout the formation of a vortex and hence the loss of atoms does not take place.

Journal of Physics Condensed Matter•Nov 27, 2002•30 citations

Fast control of topological vortex formation in Bose-Einstein condensates by counterdiabatic driving

Shumpei Masuda, Utkan Güngördü, Xi Chen +2 more

Fast creation of a single vortex in BEC of alkali-metal atoms at a prescribed position and time is still challenging, even though various methods to create single and multiple vortices have been proposed and demonstrated. Topological vortex formation is advantageous in this respect over other methods in that the position and time of vortex formation is highly controllable. This method requires inversion of the bias magnetic field along the axis of the condensate, which leads to unwanted atom loss due to nonadiabatic transitions when the bias field crosses zero. It is the purpose of this paper to propose a scheme that enables a fast creation of a vortex in much shorter time than needed for adiabatic control time by introducing the counterdiabatic field to avert the atom loss. We further introduce a gauge transformation so that the required magnetic field is generated by manipulating the current of the Ioffe bars, which makes our proposal experimentally feasible.

arXiv:1507.03052•Physical Review A•Jan 26, 2016•14 citations

Preparing topological states of a Bose–Einstein condensate

JAMES E. JUN. WILLIAMS, Murray Holland

Abstract Observations of Bose–Einstein condensates—macroscopic populations of ultracold atoms occupying a single quantum state—in dilute alkali-metal and hydrogen gases have stimulated a great deal of research into the statistical physics of weakly interacting quantum degenerate systems1, 2. Recent experiments offer a means of exploring fundamental low-temperature physics in a controllable manner. A current experimental goal in the study of trapped Bose gases is the observation of superfluid-like behaviour, analogous to the persistent currents seen in superfluid liquid helium which flow without observable viscosity. The ‘super’ properties of Bose-condensed systems occur because the macroscopic occupation of a quantized mode provides a stabilizing mechanism that inhibits decay through thermal relaxation3. Here we show how to selectively generate superfluid vortex modes with different angular momenta in a Bose–Einstein condensate. Our approach involves solving the time-dependent equation of motion of a two-component condensate with strongly coupled internal atomic states, as recently investigated experimentally4, 5. The generation of vortices relies on the coupling between the states (achieved by applying an electromagnetic field), combined with mechanical rotation of the trapping potentials which confine the condensate.

•Jan 1, 1999•170 citations
It is shown theoretically that a persistent current can be continuously created in a Bose-Einstein condensate (BEC) of alkali-metal atoms confined in a multiply connected region by making use of a spin degree of freedom of the order parameter of a BEC. We demonstrate that this persistent current is easily transformed into a vortex. Relaxation processes of these BEC after the confining field is turned off are also studied, so that our analyses are compared with time-of-flight experiments. The results are shown to clearly reflect the existence of a persistent current.
A quantized vortex in Bose-Einstein condensation (BEC) of an alkali-metal atom gas is known to be unstable intrinsically at zero temperature. We examine two stabilization mechanisms of a vortex theoretically. (i) The finite temperature effect is shown to stabilize a vortex. (ii) An additional pinning potential, which may be produced by a focused laser beam at the vortex center, is also shown to stabilize it even at zero temperature. The mean-field calculation for BEC confined by a harmonic potential is employed. The detailed properties of a stable vortex are given, such as the spatial profiles of the condensate and noncondensate, the particle current density around the core, the whole excitation spectrum, and their temperature dependence.
We describe the coherent transfer of the orbital angular momentum of a photon to an atom in quantized units of ℏ, using a 2-photon stimulated Raman process with Laguerre-Gaussian beams to generate an atomic vortex state in a Bose-Einstein condensate (BEC) of sodium atoms. We show that the process is coherent by creating superpositions of different vortex states, where the relative phase between the states is determined by the relative phases of the optical fields. We use this technique to generate circular flow of a BEC confined in a toriodal shaped trap. We measure that the flow of atoms persists for up to 10 seconds, which we interpret as the first evidence of persistent currents in a superfluid Bose gas.
It is shown that a vortex can be continuously created in a Bose-Einstein condensate with hyperfine spin F=2 in a Ioffe-Pritchard trap by reversing the axial magnetic field adiabatically. It may be speculated that the condensate cannot be confined in the trap since the weak-field seeking state makes transitions to the neutral and the strong-field seeking states due to the degeneracy of these states along the vortex axis when the axial field vanishes. We have solved the Gross-Pitaevskii equation numerically with given external magnetic fields to show that this is not the case. It is shown that a considerable fraction of the condensate remains in the trap even when the axial field is reversed rather slowly. This scenario is also analysed in the presence of an optical plug along the vortex axis. Then the condensate remains within the Fz=2F_z=2Fz​=2 manifold, with respect to the local magnetic field, throughout the formation of a vortex and hence the loss of atoms does not take place.
It is shown that a vortex can be continuously created in a Bose–Einstein condensate with hyperfine spin F = 2 in a Ioffe–Pritchard trap by reversing the axial magnetic field adiabatically. It may be speculated that the condensate cannot be confined in the trap since the weak-field seeking state makes transitions to the neutral and the strong-field seeking states due to the degeneracy of these states along the vortex axis when the axial field vanishes. We have solved the Gross–Pitaevskii equation numerically with given external magnetic fields to show that this is not the case. It is shown that a considerable fraction of the condensate remains in the trap even when the axial field is reversed rather slowly. This scenario is also analysed in the presence of an optical plug along the vortex axis. Then the condensate remains within the F z = 2 manifold, with respect to the local magnetic field, throughout the formation of a vortex and hence the loss of atoms does not take place.
Fast creation of a single vortex in BEC of alkali-metal atoms at a prescribed position and time is still challenging, even though various methods to create single and multiple vortices have been proposed and demonstrated. Topological vortex formation is advantageous in this respect over other methods in that the position and time of vortex formation is highly controllable. This method requires inversion of the bias magnetic field along the axis of the condensate, which leads to unwanted atom loss due to nonadiabatic transitions when the bias field crosses zero. It is the purpose of this paper to propose a scheme that enables a fast creation of a vortex in much shorter time than needed for adiabatic control time by introducing the counterdiabatic field to avert the atom loss. We further introduce a gauge transformation so that the required magnetic field is generated by manipulating the current of the Ioffe bars, which makes our proposal experimentally feasible.
Abstract Observations of Bose–Einstein condensates—macroscopic populations of ultracold atoms occupying a single quantum state—in dilute alkali-metal and hydrogen gases have stimulated a great deal of research into the statistical physics of weakly interacting quantum degenerate systems1, 2. Recent experiments offer a means of exploring fundamental low-temperature physics in a controllable manner. A current experimental goal in the study of trapped Bose gases is the observation of superfluid-like behaviour, analogous to the persistent currents seen in superfluid liquid helium which flow without observable viscosity. The ‘super’ properties of Bose-condensed systems occur because the macroscopic occupation of a quantized mode provides a stabilizing mechanism that inhibits decay through thermal relaxation3. Here we show how to selectively generate superfluid vortex modes with different angular momenta in a Bose–Einstein condensate. Our approach involves solving the time-dependent equation of motion of a two-component condensate with strongly coupled internal atomic states, as recently investigated experimentally4, 5. The generation of vortices relies on the coupling between the states (achieved by applying an electromagnetic field), combined with mechanical rotation of the trapping potentials which confine the condensate.