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

Physical Review Letters

Collisional Blockade in Microscopic Optical Dipole Traps

Nicolas Schlosser, G. Reymond, Philippe Grangier

Published Jun 19, 2002• 280 citations
Publisher

Abstract

We analyze the operating regimes of a very small optical dipole trap, loaded from a magneto-optical trap, as a function of the atom loading rate, i.e., the number of atoms per second entering the dipole trap. We show that, when the dipole trap volume is small enough, a "collisional blockade" mechanism locks the average number of trapped atoms on the value 0.5 over a large range of loading rates. We also discuss the "weak loading" and "strong loading" regimes outside the blockade range, and we demonstrate experimentally the existence of these three regimes.

DOI
10.1103/physrevlett.89.023005

Related papers

Single Atom Manipulation in a Microscopic Dipole Trap

G. Reymond, Nicolas Schlosser, Philippe Grangier

We describe the operation of a very small optical dipole trap that is designed to store and manipulate individual atoms. Due to the very small dipole trap volume, a “collisional blockade ” mechanism locks the average number of trapped atoms on the value 0.5 over a large range of loading rates. We demonstrate experimentally the existence of this regime, and we describe also the “weakloading ” and “strong loading ” regimes outside the blockade range. In addition, we describe methods to measure the oscillation frequencies of a single atom in the trap with a high accuracy, and a “release and recapture ” method designed for temperature measurements at the single atom level. The measured “single atom temperature ” is 35 µK, that is in the sub-Doppler regime. Finally, by exploiting the extremely high density observed in the strong loading regime, we present preliminary results for evaporative cooling, where typically 30 atoms at 200 µK are forced to evaporate into about 10 atoms at 15 µK. 1

International Conference on Atomic Physics (ICAP)•Apr 1, 2003•0 citations

Single atoms in optical traps

S. Bergamini, Benoît Darquié, Antoine Browaeys +1 more

We present a brief overview of optical trapping experiments of individual neutral atoms. Then we describe in more details an experiment using a very small optical dipole trap, that is designed to store and manipulate individual atoms. Due to the very small dipole trap volume, a "collisional blockade" mechanism locks the average number of trapped atoms on the value 0.5 over a large range of loading rates. We study this regime experimentally, and we describe methods to measure the oscillation frequencies and the temperature of a single atom in the trap with a high accuracy.

Journal de Physique IV (Proceedings)•Oct 1, 2004•1 citation

Single-atom manipulations in a microscopic dipole trap

G. Reymond, Nicolas Schlosser, Игорь Евгеньевич Проценко +1 more

We have realized a very small optical dipole trap that is designed to store and manipulate individual atoms. Due to the very small dipole-trap volume, a 'collisional blockade' mechanism locks the average number of trapped atoms at a value of 0.5 over a large range of loading rates. Here we describe methods to characterize the motion of a single trapped atom, and we also demonstrate the possibility of trapping two atoms individually at a short distance apart. Finally, we study theoretically the possibility to perform 'conditional quantum logic' by scattering photons from two such atoms.

Philosophical Transactions of the Royal Society A Mathematical Physical and Engineering Sciences•Jul 15, 2003•25 citations

Number-triggered loading and collisional redistribution of neutral atoms in a standing wave dipole trap

Leonid Förster, Wolfgang Alt, I. Dotsenko +5 more

We implement a technique for loading a preset number of up to 19 atoms from a magneto-optical trap into a standing wave optical dipole trap. The efficiency of our technique is characterized by measuring the atom number before and after the loading process. Our analysis reveals details of the trap dynamics that are usually masked when working with larger atomic ensembles. In particular, we identify a low-loss collisional blockade mechanism. It forces the atoms to redistribute in the periodic potential until they are all stored in individual trapping sites, thereby strongly reducing site occupation number fluctuations.

New Journal of Physics•Oct 27, 2006•25 citations

Loading characteristics of a microscopic optical dipole trap

P. Kulatunga, Tyler Blum, D. Olek

We report on an investigation of loading characteristics of deep microscopic dipole traps. The dipole trap is loaded from a low density magneto optical trap (MOT) containing $\approx 5\times 10^{6}$ atoms. We determine the loading parameters that maximize the trapped atom number for a trap of waist 5 μm with trap depths ranging from 3.5 mK to 10 mK. We determine the optimal trap loading conditions and the loading rates, loss coefficients and temperature of the trapped atoms under these conditions. We show that it is possible to load a few hundred to thousand atoms in dipole traps of depth 3.5 mK to 8.5 mK under the optimal loading conditions.

arXiv:1009.2544•Sep 14, 2010•0 citations

Loading an optical dipole trap

S. J. M. Kuppens, Kristan L. Corwin, Kurt W. Miller +2 more

We present a detailed experimental study of the physics involved in transferring atoms from a magneto-optical trap (MOT) to an optical dipole trap. The loading is a dynamical process determined by a loading rate and a density dependent loss rate. The loading rate depends on cooling and the flux of atoms into the trapping volume, and the loss rate is due to excited state collisions induced by the MOT light fields. From this study we found ways to optimize the loading of the optical dipole trap. Key ingredients for maximum loading are found to be a reduction of the hyperfine repump intensity, increased detuning of the MOT light, and a displacement of the optical dipole trap center with respect to the MOT. A factor of 2 increase in the number of loaded atoms is demonstrated by using a hyperfine repump beam with a shadow in it. In this way we load $8\ifmmode\times\else\texttimes\fi{}{10}^{6}{}^{85}\mathrm{Rb}$ atoms into a 1 mK deep optical dipole trap with a waist of $58 \ensuremath{\mu}\mathrm{m},$ which is 40% of the atoms initially trapped in the MOT.

Physical Review A•Jun 13, 2000•185 citations
We analyze the operating regimes of a very small optical dipole trap, loaded from a magneto-optical trap, as a function of the atom loading rate, i.e., the number of atoms per second entering the dipole trap. We show that, when the dipole trap volume is small enough, a "collisional blockade" mechanism locks the average number of trapped atoms on the value 0.5 over a large range of loading rates. We also discuss the "weak loading" and "strong loading" regimes outside the blockade range, and we demonstrate experimentally the existence of these three regimes.
We describe the operation of a very small optical dipole trap that is designed to store and manipulate individual atoms. Due to the very small dipole trap volume, a “collisional blockade ” mechanism locks the average number of trapped atoms on the value 0.5 over a large range of loading rates. We demonstrate experimentally the existence of this regime, and we describe also the “weakloading ” and “strong loading ” regimes outside the blockade range. In addition, we describe methods to measure the oscillation frequencies of a single atom in the trap with a high accuracy, and a “release and recapture ” method designed for temperature measurements at the single atom level. The measured “single atom temperature ” is 35 µK, that is in the sub-Doppler regime. Finally, by exploiting the extremely high density observed in the strong loading regime, we present preliminary results for evaporative cooling, where typically 30 atoms at 200 µK are forced to evaporate into about 10 atoms at 15 µK. 1
We present a brief overview of optical trapping experiments of individual neutral atoms. Then we describe in more details an experiment using a very small optical dipole trap, that is designed to store and manipulate individual atoms. Due to the very small dipole trap volume, a "collisional blockade" mechanism locks the average number of trapped atoms on the value 0.5 over a large range of loading rates. We study this regime experimentally, and we describe methods to measure the oscillation frequencies and the temperature of a single atom in the trap with a high accuracy.
We have realized a very small optical dipole trap that is designed to store and manipulate individual atoms. Due to the very small dipole-trap volume, a 'collisional blockade' mechanism locks the average number of trapped atoms at a value of 0.5 over a large range of loading rates. Here we describe methods to characterize the motion of a single trapped atom, and we also demonstrate the possibility of trapping two atoms individually at a short distance apart. Finally, we study theoretically the possibility to perform 'conditional quantum logic' by scattering photons from two such atoms.
We implement a technique for loading a preset number of up to 19 atoms from a magneto-optical trap into a standing wave optical dipole trap. The efficiency of our technique is characterized by measuring the atom number before and after the loading process. Our analysis reveals details of the trap dynamics that are usually masked when working with larger atomic ensembles. In particular, we identify a low-loss collisional blockade mechanism. It forces the atoms to redistribute in the periodic potential until they are all stored in individual trapping sites, thereby strongly reducing site occupation number fluctuations.
We report on an investigation of loading characteristics of deep microscopic dipole traps. The dipole trap is loaded from a low density magneto optical trap (MOT) containing ≈5×106\approx 5\times 10^{6}≈5×106 atoms. We determine the loading parameters that maximize the trapped atom number for a trap of waist 5 μm with trap depths ranging from 3.5 mK to 10 mK. We determine the optimal trap loading conditions and the loading rates, loss coefficients and temperature of the trapped atoms under these conditions. We show that it is possible to load a few hundred to thousand atoms in dipole traps of depth 3.5 mK to 8.5 mK under the optimal loading conditions.
We present a detailed experimental study of the physics involved in transferring atoms from a magneto-optical trap (MOT) to an optical dipole trap. The loading is a dynamical process determined by a loading rate and a density dependent loss rate. The loading rate depends on cooling and the flux of atoms into the trapping volume, and the loss rate is due to excited state collisions induced by the MOT light fields. From this study we found ways to optimize the loading of the optical dipole trap. Key ingredients for maximum loading are found to be a reduction of the hyperfine repump intensity, increased detuning of the MOT light, and a displacement of the optical dipole trap center with respect to the MOT. A factor of 2 increase in the number of loaded atoms is demonstrated by using a hyperfine repump beam with a shadow in it. In this way we load $8\ifmmode\times\else\texttimes\fi{}{10}^{6}{}^{85}\mathrm{Rb}$ atoms into a 1 mK deep optical dipole trap with a waist of $58 \ensuremath{\mu}\mathrm{m},$ which is 40% of the atoms initially trapped in the MOT.