Three-body recombination is a collision process where two atoms combine to form a molecule and a third atom carries away part of the released reaction energy. Here, we experimentally determine for the first time the population distribution of the molecular reaction products after a three-body recombination for non-resonant particle interactions. The key to our measurements is a sensitive detection scheme that combines the photoionization of the molecules with subsequent ion trapping. Using an ultracold 87Rb gas at very low kinetic energy below h×20 kHz, we find a broad population of final states with binding energies of up to h×750 GHz. This is in contrast with previous experiments, performed in the resonant interaction regime, that found a dominant population of only the most weakly bound molecular state or the occurrence of Efimov resonances. This work may contribute to the development of an in-depth model that can qualitatively and quantitatively predict the reaction products of three-body recombination.
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Hess, H. F. et al. Observation of three-body recombination in spin-polarized hydrogen. Phys. Rev. Lett. 51, 483–486 (1983).
Burt, E. A. et al. Coherence, correlations, and collisions: What one learns about Bose–Einstein condensates from their decay. Phys. Rev. Lett. 79, 337–340 (1997).
Söding, J. et al. Three-body decay of a rubidium Bose–Einstein condensate. Appl. Phys. B 69, 257–261 (1999).
Esry, B. D., Greene, C. H. & Burke, J. P. Recombination of three atoms in the ultracold limit. Phys. Rev. Lett. 83, 1751–1754 (1999).
Suno, H. & Esry, B. D. Three-body recombination in cold helium–helium-alkali-metal-atom collisions. Phys. Rev. A 80, 062702 (2009).
Wang, Y., D’Incao, J. P. & Esry, B. D. Cold three-body collisions in hydrogen–hydrogen-alkali-metal atomic systems. Phys. Rev. A 83, 032703 (2011).
Guevara, N. L., Wang, Y. & Esry, B. D. New class of three-body states. Phys. Rev. Lett. 108, 213202 (2012).
Fedichev, P. O., Reynolds, M. W. & Shlyapnikov, G. V. Three-body recombination of ultracold atoms to a weakly bound s level. Phys. Rev. Lett. 77, 2921–2924 (1996).
Bedaque, P. F., Braaten, E. & Hammer, H-W. Three-body recombination in Bose gases with large scattering length. Phys. Rev. Lett. 85, 908–911 (2000).
Efimov, V. Energy levels arising from resonant two-body forces in a three-body system. Phys. Lett. B 33, 563–564 (1970).
Braaten, E. & Hammer, H-W. Three-body recombination into deep bound states in a Bose gas with large scattering length. Phys. Rev. Lett. 87, 160407 (2001).
Kraemer, T. et al. Evidence for Efimov quantum states in an ultracold gas of caesium atoms. Nature 440, 315–318 (2006).
Weber, T., Herbig, J., Mark, M., Nägerl, H-C. & Grimm, R. Three-body recombination at large scattering lengths in an ultracold atomic gas. Phys. Rev. Lett. 91, 123201 (2003).
Jochim, S. et al. Pure gas of optically trapped molecules created from Fermionic atoms. Phys. Rev. Lett. 91, 240402 (2003).
Simoni, A. & Launay, J-M. Ultracold atom-molecule collisions with hyperfine coupling. Laser Phys. 16, 707–712 (2006).
Bates, D. R., Kingston, A. E. & McWhirter, R. W. P. Recombination between electrons and atomic ions. I. Optically thin plasmas. Proc. R. Soc. Lond. Ser A. 267, 297–312 (1962).
Flower, D. R. & Harris, G. J. Three-body recombination of hydrogen during primordial star formation. Mon. Not. R. Astronom. Soc. 377, 705–710 (2007).
Lozeille, J. et al. Detection by two-photon ionization and magnetic trapping of cold Rb2 triplet state molecules. Eur. Phys. J. D 39, 261–269 (2006).
Fioretti, A. et al. Formation of cold Cs2 molecules through photoassociation. Phys. Rev. Lett. 80, 4402–4405 (1998).
Gabbanini, C., Fioretti, A., Lucchesini, A., Gozzini, S. & Mazzoni, M. Cold rubidium molecules formed in a magneto-optical trap. Phys. Rev. Lett. 84, 2814–2817 (2000).
Huang, Y. et al. Formation, detection and spectroscopy of ultracold Rb2 in the ground X1Σg+ state. J. Phys. B 39, S857–S869 (2006).
Salzmann, W. et al. Coherent transients in the femtosecond photoassociation of ultracold molecules. Phys. Rev. Lett. 100, 233003 (2008).
Sullivan, S. T. et al. Trapping molecular ions formed via photo-associative ionization of ultracold atoms. Phys. Chem. Chem. Phys. 13, 18859–18863 (2011).
Mudrich, M. et al. Spectroscopy of triplet states of Rb2 by femtosecond pump–probe photoionization of doped helium nanodroplets. Phys. Rev. A 80, 042512 (2009).
Strauss, C. et al. Hyperfine, rotational, and vibrational structure of the a3Σu+ state of 87Rb2 . Phys. Rev. A 82, 052514 (2010).
Takekoshi, T. et al. Hyperfine, rotational, and Zeeman structure of thelowest vibrational levels of the 87Rb2 (1) 3Σg+ state. Phys. Rev. A 83, 062504 (2011).
Drozdova, A. Study of Spin-Orbit Coupled Electronic States of Rb 2 , NaCs and NaK Molecules. Laser Spectroscopy and Accurate Coupled-channel Deperturbation Analysis PhD thesis, Univ. de Lyon and Lomonosov State Univ. (2012).
Mukaiyama, T., Abo-Shaeer, J. R., Xu, K., Chin, J. K. & Ketterle, W. Dissociation and decay of ultracold sodium molecules. Phys. Rev. Lett. 92, 180402 (2004).
Staanum, P., Kraft, S. D., Lange, J., Wester, R. & Weidemüller, M. Experimental investigation of ultracold atom-molecule collisions. Phys. Rev. Lett. 96, 023201 (2006).
Zahzam, N., Vogt, T., Mudrich, M., Comparat, D. & Pillet, P. Atom-molecule collisions in an optically trapped gas. Phys. Rev. Lett. 96, 023202 (2006).
Quéméner, G., Launay, J-M. & Honvault, P. Ultracold collisions between Li atoms and Li2 diatoms in high vibrational states. Phys. Rev. A 75, 050701 (2007).
Schmid, S., Härter, A., Frisch, A., Hoinka, S. & Hecker Denschlag, J. An apparatus for immersing trapped ions into an ultracold gas of neutral atoms. Rev. Sci. Instrum. 83, 053108 (2012).
Schmid, S., Härter, A. & Hecker Denschlag, J. Dynamics of a cold trapped ion in a Bose–Einstein condensate. Phys. Rev. Lett. 105, 133202 (2010).
Härter, A. et al. Single ion as a three-body reaction center in an ultracold atomic gas. Phys. Rev. Lett. 109, 123201 (2012).
Aymar, M., Azizi, S. & Dulieu, O. Model-potential calculations for ground and excited Σ states of Rb2+, Cs2+ and RbCs+ ions. J. Phys. B 36, 4799–4812 (2003).
The authors would like to thank S. Schmid and A. Brunner for support during early stages of the experiment and O. Dulieu, B. Esry, J. d’Incao, W. Stwalley, U. Heinzmann, J. Hutson, P. Soldan, T. Bergeman and A. Drozdova for valuable information and fruitful discussions. This work was supported by the German Research Foundation DFG within the SFB/TRR21.
The authors declare no competing financial interests.
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Härter, A., Krükow, A., Deiß, M. et al. Population distribution of product states following three-body recombination in an ultracold atomic gas. Nature Phys 9, 512–517 (2013). https://doi.org/10.1038/nphys2661
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