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

Journal of the Optical Society of America B

Spatially localized optical pumping in Paul traps

Michael Schubert, Ingo Siemers, R. Blatt

Published Nov 1, 1989• 10 citations
Publisher

Abstract

Spatially localized optical pumping into energy eigenstates and into a long-living nonabsorbing coherent superposition of the two low-lying metastable states of the Ba+ ion has been observed. The spatial localization is traced to the properties of micromotion in Paul traps. Observed spatial distributions of the laser-induced fluorescence have been qualitatively reproduced by using a model based on the notion of velocity amplitudes and the Brownianmotion model of ion dynamics in the Paul trap.

DOI
10.1364/josab.6.002159

Related papers

Observation of Pr+Ions in Paul Trap

Jerzy Dembczyński, Danuta Stefańska, Gustaw Szawioła +11 more

The first observation of Pr+ ions stored in a Paul trap is reported.Initially the ions were observed by the electronic detection method, and further the laser induced fluorescence, following resonance absorption at a certain optical transition in Pr+ ion, which is excited from the ground state, was recorded.Moreover, fluorescence signal following the excitation from a low-lying metastable state could be detected.The Paul trap system and some other parts of tle experimental setup were constructed within the frame of this work and thus are briefly described in the present contribution.PACS numbers: 32.80.Pj of the equipment of the laser-spectroscopic laboratory to our group, and for having partially involved one of the authors (D.S.) in the experiments in the Paul trap, particularly with HΣ+ ions.Many valuable hints concerning the practical aspects of the experiments in the Paul trap are also deeply appreciated.

Acta Physica Polonica A•Sep 1, 1997•4 citations

Thermally activated hopping of two ions trapped in a bistable potential well

Klaus Abich, Albert Keil, Dirk Reiß +3 more

With two ions in a spheroidal Paul trap, the harmonic trapping potential turns, by Coulomb repulsion, into a bistable well. Two Ba ions have been confined, laser-cooled, and observed, via their laser-excited resonance scattering, by a spatially resolving photomultiplier, or intensifying CCD camera. A repump laser releases the ions from a metastable state. Well-cooled ions are found localized. When the laser is detuned, the Raman cooling rate and the ions’ temperature vary. A transition from the crystallized state to a toroidal gas takes place. The ions are discriminated when one (i) gets excited into a non-fluorescing metastable state, or (ii) is of another isotopic species. Hopping rates of 1 s −1 are found at high thermal excitation. Elsewhere, the rates drop by two orders of magnitude, and vary resonantly with temperature near potential energy/kinetic energy = 15, where the bright ion’s hopping upstream of the laser beam is five times more likely than downstream. Two discernible ions in a trap represent a microscopic model system for the study of reaction kinetics.

Journal of Optics B Quantum and Semiclassical Optics•Mar 1, 2004•9 citations

Spatial fluorescence distribution and laser cooling of Ca+in a Paul trap

Th. Gudjons, F. Arbes, M. Benzing +2 more

Experiments on Ca* ions, confined in a Paul trap, deal with the spatial distribution of the fluorescence intensity, from which information on the velocity distribution of an ion cloud can be derived.We obtained laser cooling of a large (about lo4) ion cloud.For a few or single trapped ions crystallization, "dark resonances" and quantum jumps have been observed.

Physica Scripta•Jan 1, 1995•6 citations

Spatial separation of atomic states in a laser-cooled ion crystal

Wolfgang Alt, M. Block, P. Seibert +1 more

We have produced a laser-cooled ion crystal in a linear Paul trap containing several hundred ${\mathrm{Ca}}^{+}$ ions. A portion of the ions can be excited by an additional laser to a long-lived metastable energy level that decouples them from the cooling laser radiation. The light pressure acting upon the remaining laser-cooled ions forces them into the direction of the laser beam, while the ions in the metastable state drift to the crystal side that points toward the cooling laser. Depending on the number of ions in the crystal and on the fraction of the excited ions, the spatial separation of the ions in the metastable state and the ions in the cooling cycle can be as large as several hundred micrometers.

Physical Review A•Jul 1, 1998•12 citations

Direct observation of ion micromotion in a linear Paul trap

Liudmila A. Zhukas, Maverick J. Millican, P. Švihra +2 more

In this paper, direct observation of micromotion for multiple ions in a laser-cooled trapped ion crystal is discussed along with a measurement technique for micromotion amplitude. Micromotion is directly observed using a time-resolving, single-photon-sensitive camera that provides both fluorescence and position data for each ion on the nanosecond time scale. Micromotion amplitude and phase for each ion in the crystal are measured, allowing this method to be sensitive to tilts and shifts of the ion chain from the null of the radio-frequency quadrupole potential in the linear trap. Spatial resolution makes this micromotion detection technique suitable for complex ion configurations, including two-dimensional geometries. It does not require any additional equipment or laser beams, and the modulation of the cooling lasers or trap voltages is not necessary for detection as it is in other methods.

arXiv:2010.00159•Physical Review A•Feb 11, 2021•28 citations

Dynamics of ion clouds in Paul traps

Ingo Siemers, R. Blatt, Thilo Sauter +1 more

Velocity distribution and spatial distribution of ion clouds in Paul traps have been investigated both theoretically and experimentally. The kinetic energy and the width of the spatial distribution have been measured as function of the trap parameters. This is compared with theoretical results obtained from model calculations based on Brownian motion of trapped particles.

Physical Review A•Nov 1, 1988•55 citations
Spatially localized optical pumping into energy eigenstates and into a long-living nonabsorbing coherent superposition of the two low-lying metastable states of the Ba+ ion has been observed. The spatial localization is traced to the properties of micromotion in Paul traps. Observed spatial distributions of the laser-induced fluorescence have been qualitatively reproduced by using a model based on the notion of velocity amplitudes and the Brownianmotion model of ion dynamics in the Paul trap.
The first observation of Pr+ ions stored in a Paul trap is reported.Initially the ions were observed by the electronic detection method, and further the laser induced fluorescence, following resonance absorption at a certain optical transition in Pr+ ion, which is excited from the ground state, was recorded.Moreover, fluorescence signal following the excitation from a low-lying metastable state could be detected.The Paul trap system and some other parts of tle experimental setup were constructed within the frame of this work and thus are briefly described in the present contribution.PACS numbers: 32.80.Pj of the equipment of the laser-spectroscopic laboratory to our group, and for having partially involved one of the authors (D.S.) in the experiments in the Paul trap, particularly with HΣ+ ions.Many valuable hints concerning the practical aspects of the experiments in the Paul trap are also deeply appreciated.
With two ions in a spheroidal Paul trap, the harmonic trapping potential turns, by Coulomb repulsion, into a bistable well. Two Ba ions have been confined, laser-cooled, and observed, via their laser-excited resonance scattering, by a spatially resolving photomultiplier, or intensifying CCD camera. A repump laser releases the ions from a metastable state. Well-cooled ions are found localized. When the laser is detuned, the Raman cooling rate and the ions’ temperature vary. A transition from the crystallized state to a toroidal gas takes place. The ions are discriminated when one (i) gets excited into a non-fluorescing metastable state, or (ii) is of another isotopic species. Hopping rates of 1 s −1 are found at high thermal excitation. Elsewhere, the rates drop by two orders of magnitude, and vary resonantly with temperature near potential energy/kinetic energy = 15, where the bright ion’s hopping upstream of the laser beam is five times more likely than downstream. Two discernible ions in a trap represent a microscopic model system for the study of reaction kinetics.
We have produced a laser-cooled ion crystal in a linear Paul trap containing several hundred Ca+{\mathrm{Ca}}^{+}Ca+ ions. A portion of the ions can be excited by an additional laser to a long-lived metastable energy level that decouples them from the cooling laser radiation. The light pressure acting upon the remaining laser-cooled ions forces them into the direction of the laser beam, while the ions in the metastable state drift to the crystal side that points toward the cooling laser. Depending on the number of ions in the crystal and on the fraction of the excited ions, the spatial separation of the ions in the metastable state and the ions in the cooling cycle can be as large as several hundred micrometers.
In this paper, direct observation of micromotion for multiple ions in a laser-cooled trapped ion crystal is discussed along with a measurement technique for micromotion amplitude. Micromotion is directly observed using a time-resolving, single-photon-sensitive camera that provides both fluorescence and position data for each ion on the nanosecond time scale. Micromotion amplitude and phase for each ion in the crystal are measured, allowing this method to be sensitive to tilts and shifts of the ion chain from the null of the radio-frequency quadrupole potential in the linear trap. Spatial resolution makes this micromotion detection technique suitable for complex ion configurations, including two-dimensional geometries. It does not require any additional equipment or laser beams, and the modulation of the cooling lasers or trap voltages is not necessary for detection as it is in other methods.