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/0607170 · Physical Review A

Atom counting in ultracold gases using photoionization and ion detection

T. J. Campey, Chris J. Vale, Matthew J. Davis, N. R. Heckenberg, Halina H. Rubinsztein-Dunlop, Sebastian Kraft, Claus Zimmermann, József Fortágh

Published Oct 18, 2006• 15 citations
arXivHTMLPDF

Abstract

We analyze photoionization and ion detection as a means of accurately counting ultracold atoms. We show that it is possible to count clouds containing many thousands of atoms with accuracies better than ${N}^{\ensuremath{-}1∕2}$ with current technology. This allows the direct probing of sub-Poissonian number statistics of atomic samples. The scheme can also be used for efficient single-atom detection with high spatiotemporal resolution. All aspects of a realistic detection scheme are considered, and we discuss experimental situations in which such a scheme could be implemented.

DOI
10.1103/physreva.74.043612

Related papers

Atom detection and counting in ultracold gases using photoionisation and ion detection

T. J. Campey

In recent years there has been increasing interest in quantum atom optics, in which the discretenature of atoms plays an important role. As such, the ability to resolve atoms at the singleatom level has become important.This thesis investigates detecting atoms using photoionisation and ion detection. Thismethod is applicable to all atoms in common use in atom optics experiments, enables theirdetection with high e±ciency, allows atom counting with sub-Poissonian resolution (¾N < pN)and is applicable for large atom numbers (up to » 105). Two approaches towards atom detectionvia photoionisation and ion detection are examined, di®ering in the rate of photoionisation. Fastphotoionisation of individual atoms can be used for detecting a series of single atoms, such asmight be produced with an atom laser. Slow ionisation is required for counting large numbersof atoms contained in a single region, due to the necessity of being able to resolve the individualions with the ion detector. The application of these methods to 87Rb is examined, althoughthey can be adapted to other atoms.The scheme for quickly detecting single atoms uses STImulated Raman Adiabatic Passage(STIRAP) to excite 87Rb atoms to the 5D5=2 level followed by ionisation from this level usinga Nd:YAG laser pulse. Simulations and experiments were carried out and used to predict thatexcitation to the 5D5=2 level can be achieved with close to 100% e±ciency, and to show theexperimental parameters required. The photoionisation cross-section of 87Rb in the 5D5=2 stateusing 1064 nm light was measured in order to predict the photoionisation e±ciency that maybe achieved, which was found to approach 100%.The scheme for atom counting uses 2£778 nm photon excitation to raise atoms to the5D5=2 state followed by ionisation from this state using a cw Nd:YAG laser. The statisticsof atom counting are examined and used to ¯nd the counting accuracy as a function of thedetection e±ciency and its uncertainty. For a precisely calibrated detector, sub-Poissoniancounting is possible for detection e±ciencies greater than 50%. The e®ect of losses and the useof the scheme for measuring number squeezing are examined. Achieving low count uncertaintiesrequires measuring the ion detection e±ciency to high accuracy. A method for doing this isproposed and analysed, and experiments were carried out to measure the ion detection e±ciencyof an ion detector in a mock experimental setup. A detailed scheme is proposed and analysed for measuring number di®erence squeezing ina RF induced double well potential using atom counting via photoionisation and ion detection.Simulations of the double well potential were performed to show how even splitting can beachieved and the degree of squeezing expected to occur. A design for an experimental setup isdescribed and analysed in detail, in order to show the accuracy with which number di®erencesqueezing can be measured.

•Jan 1, 2009•0 citations

Single-atom detection on a chip: from realization to application

Alexander Stibor, H. Bender, S Kühnhold +3 more

In this paper, we describe the preparation and detection of ultracold atoms on a microchip with single-atom sensitivity. The detection scheme is based on multi-photon ionization of atoms and the subsequent guiding of the generated ions by ion optics to a channel electron multiplier. We resolve single atoms with a detection efficiency above 60%. The detector is suitable for real-time observations of static and dynamic processes in ultracold quantum gases. Although the ionization is destructive, sampling a small subset of the atomic distribution is sufficient for the determination of the desired information. We take full high-resolution spectra of ultracold atoms by ionizing only 5% of the atoms. Using an additional microwave near 6.8 GHz, the detection scheme becomes energy, position and state selective. This can be used for in situ determination of the energy distribution and temperature of atom clouds inside the trap and applied for future correlation measurements.

New Journal of Physics•Jun 28, 2010•15 citations

Highly Efficient State-Selective Submicrosecond Photoionization Detection of Single Atoms

Florian Henkel, Michael Krug, Julian Hofmann +3 more

We experimentally demonstrate a detection scheme suitable for state analysis of single optically trapped atoms in less than 1 μs with an overall detection efficiency η exceeding 98%. The method is based on hyperfine-state-selective photoionization and subsequent registration of the correlated photoion-electron pairs by coincidence counting via two opposing channel electron multipliers. The scheme enables the calibration of absolute detection efficiencies and might be a key ingredient for future quantum information applications or precision spectroscopy of ultracold atoms.

arXiv:1008.1910•Physical Review Letters•Dec 13, 2010•35 citations

A scanning electron microscope for ultracold atoms

Tatjana Gericke, C. Utfeld, N Hommerstad +1 more

We propose a new technique for the detection of single atoms in ultracold quantum gases. The technique is based on scanning electron microscopy and employs the electron impact ionization of trapped atoms with a focused electron probe. Subsequent detection of the resulting ions allows for the reconstruction of the atom's position. This technique is expected to achieve a much better spatial resolution compared to any optical detection method. In combination with the sensitivity to single atoms, it makes new in situ measurements of atomic correlations possible. The detection principle is also well suited for the addressing of individual sites in optical lattices.

arXiv:cond-mat/0607358•Laser Physics Letters•May 11, 2006•18 citations

Single atom detection in ultracold quantum gases: a review of current progress

Herwig Ott

The recent advances in single atom detection and manipulation in experiments with ultracold quantum gases are reviewed. The discussion starts with the basic principles of trapping, cooling and detecting single ions and atoms. The realization of single atom detection in ultracold quantum gases is presented in detail and the employed methods, which are based on light scattering, electron scattering, field ionization and direct neutral particle detection are discussed. The microscopic coherent manipulation of single atoms in a quantum gas is also covered. Various examples are given in order to highlight the power of these approaches to study many-body quantum systems.

arXiv:1602.08422•Reports on Progress in Physics•Apr 18, 2016•101 citations

Optical Spectroscopy of Ultracold Atoms on an Atom Chip

Andreas Günther, H. Bender, Alexander Stibor +2 more

We experimentally demonstrate optical spectroscopy of magnetically trapped atoms on an atom chip. High resolution optical spectra of individual trapped clouds are recorded within a few hundred milliseconds. Detection sensitivities close to the single atom level are obtained by photoionization of the excited atoms and subsequent ion detection with a channel electron multiplier. Temperature and decay rates of the trapped atomic cloud can be monitored in real time for several seconds with only little detection losses. The spectrometer can be used for investigations of ultracold atomic mixtures and for the development of interferometric quantum sensors on atom chips.

arXiv:0809.2527•Sep 15, 2008•0 citations
We analyze photoionization and ion detection as a means of accurately counting ultracold atoms. We show that it is possible to count clouds containing many thousands of atoms with accuracies better than N\ensuremath−1∕2{N}^{\ensuremath{-}1∕2}N\ensuremath−1∕2 with current technology. This allows the direct probing of sub-Poissonian number statistics of atomic samples. The scheme can also be used for efficient single-atom detection with high spatiotemporal resolution. All aspects of a realistic detection scheme are considered, and we discuss experimental situations in which such a scheme could be implemented.
In recent years there has been increasing interest in quantum atom optics, in which the discretenature of atoms plays an important role. As such, the ability to resolve atoms at the singleatom level has become important.This thesis investigates detecting atoms using photoionisation and ion detection. Thismethod is applicable to all atoms in common use in atom optics experiments, enables theirdetection with high e±ciency, allows atom counting with sub-Poissonian resolution (¾N < pN)and is applicable for large atom numbers (up to » 105). Two approaches towards atom detectionvia photoionisation and ion detection are examined, di®ering in the rate of photoionisation. Fastphotoionisation of individual atoms can be used for detecting a series of single atoms, such asmight be produced with an atom laser. Slow ionisation is required for counting large numbersof atoms contained in a single region, due to the necessity of being able to resolve the individualions with the ion detector. The application of these methods to 87Rb is examined, althoughthey can be adapted to other atoms.The scheme for quickly detecting single atoms uses STImulated Raman Adiabatic Passage(STIRAP) to excite 87Rb atoms to the 5D5=2 level followed by ionisation from this level usinga Nd:YAG laser pulse. Simulations and experiments were carried out and used to predict thatexcitation to the 5D5=2 level can be achieved with close to 100% e±ciency, and to show theexperimental parameters required. The photoionisation cross-section of 87Rb in the 5D5=2 stateusing 1064 nm light was measured in order to predict the photoionisation e±ciency that maybe achieved, which was found to approach 100%.The scheme for atom counting uses 2£778 nm photon excitation to raise atoms to the5D5=2 state followed by ionisation from this state using a cw Nd:YAG laser. The statisticsof atom counting are examined and used to ¯nd the counting accuracy as a function of thedetection e±ciency and its uncertainty. For a precisely calibrated detector, sub-Poissoniancounting is possible for detection e±ciencies greater than 50%. The e®ect of losses and the useof the scheme for measuring number squeezing are examined. Achieving low count uncertaintiesrequires measuring the ion detection e±ciency to high accuracy. A method for doing this isproposed and analysed, and experiments were carried out to measure the ion detection e±ciencyof an ion detector in a mock experimental setup. A detailed scheme is proposed and analysed for measuring number di®erence squeezing ina RF induced double well potential using atom counting via photoionisation and ion detection.Simulations of the double well potential were performed to show how even splitting can beachieved and the degree of squeezing expected to occur. A design for an experimental setup isdescribed and analysed in detail, in order to show the accuracy with which number di®erencesqueezing can be measured.
In this paper, we describe the preparation and detection of ultracold atoms on a microchip with single-atom sensitivity. The detection scheme is based on multi-photon ionization of atoms and the subsequent guiding of the generated ions by ion optics to a channel electron multiplier. We resolve single atoms with a detection efficiency above 60%. The detector is suitable for real-time observations of static and dynamic processes in ultracold quantum gases. Although the ionization is destructive, sampling a small subset of the atomic distribution is sufficient for the determination of the desired information. We take full high-resolution spectra of ultracold atoms by ionizing only 5% of the atoms. Using an additional microwave near 6.8 GHz, the detection scheme becomes energy, position and state selective. This can be used for in situ determination of the energy distribution and temperature of atom clouds inside the trap and applied for future correlation measurements.
We experimentally demonstrate a detection scheme suitable for state analysis of single optically trapped atoms in less than 1 μs with an overall detection efficiency η exceeding 98%. The method is based on hyperfine-state-selective photoionization and subsequent registration of the correlated photoion-electron pairs by coincidence counting via two opposing channel electron multipliers. The scheme enables the calibration of absolute detection efficiencies and might be a key ingredient for future quantum information applications or precision spectroscopy of ultracold atoms.
We propose a new technique for the detection of single atoms in ultracold quantum gases. The technique is based on scanning electron microscopy and employs the electron impact ionization of trapped atoms with a focused electron probe. Subsequent detection of the resulting ions allows for the reconstruction of the atom's position. This technique is expected to achieve a much better spatial resolution compared to any optical detection method. In combination with the sensitivity to single atoms, it makes new in situ measurements of atomic correlations possible. The detection principle is also well suited for the addressing of individual sites in optical lattices.
The recent advances in single atom detection and manipulation in experiments with ultracold quantum gases are reviewed. The discussion starts with the basic principles of trapping, cooling and detecting single ions and atoms. The realization of single atom detection in ultracold quantum gases is presented in detail and the employed methods, which are based on light scattering, electron scattering, field ionization and direct neutral particle detection are discussed. The microscopic coherent manipulation of single atoms in a quantum gas is also covered. Various examples are given in order to highlight the power of these approaches to study many-body quantum systems.
We experimentally demonstrate optical spectroscopy of magnetically trapped atoms on an atom chip. High resolution optical spectra of individual trapped clouds are recorded within a few hundred milliseconds. Detection sensitivities close to the single atom level are obtained by photoionization of the excited atoms and subsequent ion detection with a channel electron multiplier. Temperature and decay rates of the trapped atomic cloud can be monitored in real time for several seconds with only little detection losses. The spectrometer can be used for investigations of ultracold atomic mixtures and for the development of interferometric quantum sensors on atom chips.