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:0801.3362 · Physical Review A

ac electric trapping of neutral atoms

Sophie Schlunk, Adela Marian, Wieland Schöllkopf, Gerard Meijer

Published Apr 11, 2008• 3 citations
arXivHTMLPDF

Abstract

We study the dynamic behavior of ultracold neutral atoms in a macroscopic ac electric trap. Confinement in such a trap is achieved by switching between two saddle-point configurations of the electric field. The gradual formation of a stably trapped cloud is observed and the trap performance is studied versus the switching frequency and the symmetry of the switching cycle. Additionally, the electric field in the trap is mapped out by imaging the atom cloud while the fields are still on. Finally, the phase-space acceptance of the trap is probed by introducing a modified switching cycle. The experimental results are reproduced using full three-dimensional trajectory calculations.

DOI
10.1103/physreva.77.043408

Related papers

Trapping of Rb Atoms by ac Electric Fields

Sophie Schlunk, Adela Marian, Peter Geng +3 more

We demonstrate trapping of an ultracold gas of neutral atoms in a macroscopic ac electric trap. Three-dimensional confinement is obtained by switching between two saddle-point configurations of the electric field. Stable trapping is observed in a narrow range of switching frequencies around 60 Hz. The dynamic confinement of the atoms is directly visualized at different phases of the ac switching cycle. We observe about 10(5) Rb atoms in the 1 mm3 large and several microkelvins deep trap with a lifetime of approximately 5 s.

arXiv:physics/0702119•Physical Review Letters•May 30, 2007•30 citations

ac Electric Trap for Ground-State Molecules

Jacqueline van Veldhoven, Hendrick L. Bethlem, Gerard Meijer

We here report on the realization of an electrodynamic trap, capable of trapping neutral atoms and molecules in both low-field and high-field seeking states. Confinement in three dimensions is achieved by switching between two electric field configurations that have a saddle point at the center of the trap, i.e., by alternating a focusing and a defocusing force in each direction. The ac trapping of 15ND(3) molecules is experimentally demonstrated, and the stability of the trap is studied as a function of the switching frequency. A 1 mK sample of 15ND(3) molecules in the high-field seeking component of the |J,K=|1,1 level, the ground state of para-ammonia, is trapped in a volume of about 1 mm(3).

arXiv:physics/0501092•Physical Review Letters•Mar 1, 2005•140 citations

Electric Trapping of Neutral Atoms

Fujio Shimizu Fujio Shimizu, Makoto Morinaga

Two- and three-dimensional trappings of neutral atoms by an electric field are discussed. It is shown that a harmonic potential produced by the second-order Stark effect around a saddle point of the electric field intensity can be used to trap laser-cooled neutral atoms.

Japanese Journal of Applied Physics•Dec 1, 1992•23 citations

Trapping polar molecules in an ac trap

Hendrick L. Bethlem, Jacqueline van Veldhoven, Melanie Schnell +1 more

Polar molecules in high-field seeking states cannot be trapped in static traps as Maxwell's equations do not allow a maximum of the electric field in free space. It is possible to generate an electric field that has a saddle point by superposing an inhomogeneous electric field to an homogeneous electric field. In such a field, molecules are focused along one direction, while being defocused along the other. By reversing the direction of the inhomogeneous electric field the focusing and defocusing directions are reversed. When the fields are being switched back and forth at the appropriate rate, this leads to a net focusing force in all directions. We describe possible electrode geometries for creating the desired fields and discuss their merits. Trapping of $^{15}\mathrm{ND}_{3}$ ammonia molecules in a cylindrically symmetric ac trap is demonstrated. We present measurements of the spatial distribution of the trapped cloud as a function of the settings of the trap and compare these to both a simple model assuming a linear force and to full three-dimensional simulations of the experiment. With the optimal settings, molecules within a phase-space volume of $270\phantom{\rule{0.3em}{0ex}}{\mathrm{mm}}^{3}\phantom{\rule{0.2em}{0ex}}(\mathrm{m}∕\mathrm{s}{)}^{3}$ remain trapped. This corresponds to a trap depth of about $5\phantom{\rule{0.3em}{0ex}}\mathrm{mK}$ and a trap volume of about $20\phantom{\rule{0.3em}{0ex}}{\mathrm{mm}}^{3}$.

Physical Review A•Dec 5, 2006•47 citations

Trapping of Neutral Rubidium with a Macroscopic Three-Phase Electric Trap

T. Rieger, Patrick Windpassinger, S. A. Rangwala +2 more

We trap neutral ground-state rubidium atoms in a macroscopic trap based on purely electric fields. For this, three electrostatic field configurations are alternated in a periodic manner. The rubidium is precooled in a magneto-optical trap, transferred into a magnetic trap, and then translated into the electric trap. The electric trap consists of six rod-shaped electrodes in cubic arrangement, giving ample optical access. Up to 10;{5} atoms have been trapped with an initial temperature of around 20 microkelvin in the three-phase electric trap. The observations are in good agreement with detailed numerical simulations.

arXiv:0707.1703•Physical Review Letters•Aug 6, 2007•21 citations

Progress Towards Confinement of an Ultracold Neutral Plasma with Electric and Magnetic Fields

Farley, Ben

Ultracold neutral plasmas represent a regime of plasmas that is not entirely described by theory, but is critical to our understanding of many phenomena. Though their low temperature makes observing them more manageable, even "confined" ultracold plasmas do not remain contained for more than a few hundred microseconds. No steady state or long-term confinement of an ultracold plasma created by pulse ionization has ever been demonstrated. In this thesis, the construction of a Penning trap for calcium ultracold neutral plasma is presented. The trap consists of a uniform magnetic field to trap the electrons radially and a quadrupole electric field to trap them in the axial direction, under the hypothesis that the space charge of the electrons will trap the ions. To the best of the author's knowledge, no ion trap of this configuration has been used to confine ultracold neutral plasmas. In addition to the Penning trap, this thesis also presents work done on other projects. This includes data acquisition and analysis on freely expanding ultracold neutral plasmas with varying density gradients, research on dielectric discharge barrier plasmas, and presentations given on these subjects. Finally, a short list of skills developed over the course of this program is given.

•Sep 4, 2025•0 citations
We study the dynamic behavior of ultracold neutral atoms in a macroscopic ac electric trap. Confinement in such a trap is achieved by switching between two saddle-point configurations of the electric field. The gradual formation of a stably trapped cloud is observed and the trap performance is studied versus the switching frequency and the symmetry of the switching cycle. Additionally, the electric field in the trap is mapped out by imaging the atom cloud while the fields are still on. Finally, the phase-space acceptance of the trap is probed by introducing a modified switching cycle. The experimental results are reproduced using full three-dimensional trajectory calculations.
We demonstrate trapping of an ultracold gas of neutral atoms in a macroscopic ac electric trap. Three-dimensional confinement is obtained by switching between two saddle-point configurations of the electric field. Stable trapping is observed in a narrow range of switching frequencies around 60 Hz. The dynamic confinement of the atoms is directly visualized at different phases of the ac switching cycle. We observe about 10(5) Rb atoms in the 1 mm3 large and several microkelvins deep trap with a lifetime of approximately 5 s.
We here report on the realization of an electrodynamic trap, capable of trapping neutral atoms and molecules in both low-field and high-field seeking states. Confinement in three dimensions is achieved by switching between two electric field configurations that have a saddle point at the center of the trap, i.e., by alternating a focusing and a defocusing force in each direction. The ac trapping of 15ND(3) molecules is experimentally demonstrated, and the stability of the trap is studied as a function of the switching frequency. A 1 mK sample of 15ND(3) molecules in the high-field seeking component of the |J,K=|1,1 level, the ground state of para-ammonia, is trapped in a volume of about 1 mm(3).
Polar molecules in high-field seeking states cannot be trapped in static traps as Maxwell's equations do not allow a maximum of the electric field in free space. It is possible to generate an electric field that has a saddle point by superposing an inhomogeneous electric field to an homogeneous electric field. In such a field, molecules are focused along one direction, while being defocused along the other. By reversing the direction of the inhomogeneous electric field the focusing and defocusing directions are reversed. When the fields are being switched back and forth at the appropriate rate, this leads to a net focusing force in all directions. We describe possible electrode geometries for creating the desired fields and discuss their merits. Trapping of 15ND3^{15}\mathrm{ND}_{3}15ND3​ ammonia molecules in a cylindrically symmetric ac trap is demonstrated. We present measurements of the spatial distribution of the trapped cloud as a function of the settings of the trap and compare these to both a simple model assuming a linear force and to full three-dimensional simulations of the experiment. With the optimal settings, molecules within a phase-space volume of 270mm3(m∕s)3270\phantom{\rule{0.3em}{0ex}}{\mathrm{mm}}^{3}\phantom{\rule{0.2em}{0ex}}(\mathrm{m}∕\mathrm{s}{)}^{3}270mm3(m∕s)3 remain trapped. This corresponds to a trap depth of about 5mK5\phantom{\rule{0.3em}{0ex}}\mathrm{mK}5mK and a trap volume of about 20mm320\phantom{\rule{0.3em}{0ex}}{\mathrm{mm}}^{3}20mm3.
We trap neutral ground-state rubidium atoms in a macroscopic trap based on purely electric fields. For this, three electrostatic field configurations are alternated in a periodic manner. The rubidium is precooled in a magneto-optical trap, transferred into a magnetic trap, and then translated into the electric trap. The electric trap consists of six rod-shaped electrodes in cubic arrangement, giving ample optical access. Up to 10;{5} atoms have been trapped with an initial temperature of around 20 microkelvin in the three-phase electric trap. The observations are in good agreement with detailed numerical simulations.
Ultracold neutral plasmas represent a regime of plasmas that is not entirely described by theory, but is critical to our understanding of many phenomena. Though their low temperature makes observing them more manageable, even "confined" ultracold plasmas do not remain contained for more than a few hundred microseconds. No steady state or long-term confinement of an ultracold plasma created by pulse ionization has ever been demonstrated. In this thesis, the construction of a Penning trap for calcium ultracold neutral plasma is presented. The trap consists of a uniform magnetic field to trap the electrons radially and a quadrupole electric field to trap them in the axial direction, under the hypothesis that the space charge of the electrons will trap the ions. To the best of the author's knowledge, no ion trap of this configuration has been used to confine ultracold neutral plasmas. In addition to the Penning trap, this thesis also presents work done on other projects. This includes data acquisition and analysis on freely expanding ultracold neutral plasmas with varying density gradients, research on dielectric discharge barrier plasmas, and presentations given on these subjects. Finally, a short list of skills developed over the course of this program is given.