Abstract
The ability to cool and slow atoms with light for subsequent trapping1,2,3 allows investigations of the properties and interactions of the trapped atoms in unprecedented detail. By contrast, the complex structure of molecules prohibits this type of manipulation, but magnetic trapping of calcium hydride molecules thermalized in ultra-cold buffer gas4 and optical trapping of caesium dimers5 generated from ultra-cold caesium atoms have been reported. However, these methods depend on the target molecules being paramagnetic or able to form through the association of atoms amenable to laser cooling6,7,8, respectively, thus restricting the range of species that can be studied. Here we describe the slowing of an adiabatically cooled beam of deuterated ammonia molecules by time-varying inhomogeneous electric fields9,10 and subsequent loading into an electrostatic trap. We are able to trap state-selected ammonia molecules with a density of 106 cm-3 in a volume of 0.25 cm3 at temperatures below 0.35 K. We observe pronounced density oscillations caused by the rapid switching of the electric fields during loading of the trap. Our findings illustrate that polar molecules can be efficiently cooled and trapped, thus providing an opportunity to study collisions and collective quantum effects in a wide range of ultra-cold molecular systems11,12,13,14.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 51 print issues and online access
$199.00 per year
only $3.90 per issue
Buy this article
- Purchase on Springer Link
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
References
Chu, S. Manipulation of neutral particles. Rev. Mod. Phys. 70, 685–706 (1998).
Cohen-Tannoudji, C. N. Manipulating atoms with photons. Rev. Mod. Phys. 70 , 707–719 (1998).
Phillips, W. D. Laser cooling and trapping of neutral atoms. Rev. Mod. Phys. 70, 721–741 (1998).
Weinstein, J. D., de Carvalho, R., Guillet, T., Friedrich, B. & Doyle, J. M. Magnetic trapping of calcium monohydride molecules at millikelvin temperatures. Nature 395, 148–150 (1998).
Takekoshi, T., Patterson, B. M. & Knize, R. J. Observation of optically trapped cold cesium molecules. Phys. Rev. Lett. 81, 5105– 5108 (1998).
Band, Y. B. & Julienne, P. S. Ultracold-molecule production by laser-cooled atom photoassociation. Phys. Rev. A 51, R4317–R4320 (1995).
Fioretti, A. et al. Formation of cold Cs2 molecules through photoassociation. Phys. Rev. Lett. 80, 4402– 4405 (1998).
Nikolov, A. N. et al. Observation of ultracold ground-state potassium molecules. Phys. Rev. Lett. 82, 703– 706 (1999).
Bethlem, H. L., Berden, G. & Meijer, G. Decelerating neutral dipolar molecules. Phys. Rev. Lett. 83, 1558–1561 (1999).
Bethlem, H. L., Berden, G., van Roij, A. J. A., Crompvoets, F. M. H. & Meijer, G. Trapping neutral molecules in traveling potential well. Phys. Rev. Lett. 84, 5744–5747 (2000).
Doyle, J. M. & Friedrich, B. Molecules are cool. Nature 401, 749–751 ( 1999).
Williams, C. J. & Julienne, P. S. Molecules at rest. Science 287, 986– 987 (2000).
Wynar, R., Freeland, R. S., Han, D. J., Ryu, C. & Heinzen, D. J. Molecules in a Bose-Einstein condensate. Science 287, 1016– 1019 (2000).
Herschbach, D. Molecular clouds, clusters, and corrals. Rev. Mod. Phys. 71, S411–S418 (1999).
Maddi, J. A., Dinneen, T. P. & Gould, H. Slowing and cooling molecules and neutral atoms by time-varying electric-field gradients. Phys. Rev. A 60, 3882–3891 (1999).
Gupta, M. & Herschbach, D. A mechanical means to produce intense beams of slow molecules. J. Phys. Chem. A 103 , 10670–10673 (1999).
Friedrich, B. Slowing of supersonically cooled atoms and molecules by time-varying nonresonant induced dipole forces. Phys. Rev. A 61, 025403-1/4 (2000).
Friedrich, B. et al. Towards magnetic trapping of molecules. J. Chem. Soc. Faraday Trans. 94, 1783–1791 (1998).
Wing, W. H. Electrostatic trapping of neutral atomic particles. Phys. Rev. Lett. 45, 631–634 ( 1980).
Gandhi, S. R. & Bernstein, R. B. Focusing and state selection of NH3 and OCS by the electrostatic hexapole via first- and second-order Stark effects. J. Chem. Phys. 87, 6457– 6467 (1987).
Ashfold, M. N. R., Dixon, R. N., Little, N., Stickland, R. J. & Western, C. M. The B1E″ state of ammonia: sub-Doppler spectroscopy at vacuum ultraviolet energies. J. Chem. Phys. 89, 1754–1761 (1988).
Bahns, J. T., Gould, P. L. & Stwalley, W. C. Formation of cold (T ≤ 1 K) molecules. Adv. At. Mol. Opt. Phys. 42, 171–224 (2000).
Acknowledgements
This work is part of the research program of the ‘Stichting voor Fundamenteel Onderzoek der Materie (FOM)’, which is financially supported by the ‘Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO)’. The research of R.T.J. has been made possible by a fellowship of the Royal Netherlands Academy of Arts and Sciences. We acknowledge the technical assistance of Ch. Timmer.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Bethlem, H., Berden, G., Crompvoets, F. et al. Electrostatic trapping of ammonia molecules. Nature 406, 491–494 (2000). https://doi.org/10.1038/35020030
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1038/35020030
This article is cited by
-
Collisions between cold molecules in a superconducting magnetic trap
Nature (2019)
-
A versatile electrostatic trap with open optical access
Frontiers of Physics (2018)
-
Terahertz Frequency Metrology for Spectroscopic Applications: a Review
Journal of Infrared, Millimeter, and Terahertz Waves (2017)
-
A novel molecular synchrotron for cold collision and EDM experiments
Scientific Reports (2016)
-
Raman gas self-organizing into deep nano-trap lattice
Nature Communications (2016)
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.
