Demagnetization cooling of a gas

ABSTRACT Adiabatic demagnetization is an efficient technique for cooling solid samples by several orders of magnitude in a single cooling step. In gases, the required coupling between

dipolar moments and motion is typically too weak, but in dipolar gases—of high-spin atoms or heteronuclear molecules with strong electric dipole moments, for example—the method should be

applicable. Here, we demonstrate demagnetization cooling of a gas of ultracold 52Cr atoms. Demagnetization is driven by inelastic dipolar collisions, which couple the motional degrees of

freedom to the spin degree. In this way, kinetic energy is converted into magnetic work, with a consequent temperature reduction of the gas. Optical pumping is used to magnetize the system

and drive continuous demagnetization cooling. We can increase the phase-space density of our sample by up to one order of magnitude, with almost no atom loss, suggesting that the method

could be used to achieve quantum degeneracy via optical means. Access through your institution Buy or subscribe This is a preview of subscription content, access via your institution ACCESS

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encouragement and practical help. We thank G. J. Beirne for careful reading of the manuscript. This work was supported by the German Science Foundation (DFG) (SPP1116 and SFB/TR 21). AUTHOR

INFORMATION AUTHORS AND AFFILIATIONS * 5. Physikalisches Institut, Universität Stuttgart, Pfaffenwaldring 57, 70550 Stuttgart, Germany M. Fattori, T. Koch, S. Goetz, A. Griesmaier, S.

Hensler, J. Stuhler & T. Pfau Authors * M. Fattori View author publications You can also search for this author inPubMed Google Scholar * T. Koch View author publications You can also

search for this author inPubMed Google Scholar * S. Goetz View author publications You can also search for this author inPubMed Google Scholar * A. Griesmaier View author publications You

can also search for this author inPubMed Google Scholar * S. Hensler View author publications You can also search for this author inPubMed Google Scholar * J. Stuhler View author

publications You can also search for this author inPubMed Google Scholar * T. Pfau View author publications You can also search for this author inPubMed Google Scholar CONTRIBUTIONS M.F.,

T.K. and S.G. carried out the experimental work and data analysis, A.G. carried out experimental work and S.H., J.S. and T.P. were responsible for project planning. CORRESPONDING AUTHORS

Correspondence to M. Fattori or T. Pfau. ETHICS DECLARATIONS COMPETING INTERESTS The authors declare no competing financial interests. RIGHTS AND PERMISSIONS Reprints and permissions ABOUT

THIS ARTICLE CITE THIS ARTICLE Fattori, M., Koch, T., Goetz, S. _et al._ Demagnetization cooling of a gas. _Nature Phys_ 2, 765–768 (2006). https://doi.org/10.1038/nphys443 Download citation

* Received: 18 July 2006 * Accepted: 02 October 2006 * Published: 29 October 2006 * Issue Date: November 2006 * DOI: https://doi.org/10.1038/nphys443 SHARE THIS ARTICLE Anyone you share the

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