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  • Letter
  • Open Access

Engineering the sub-Doppler force in magneto-optical traps

S. Xu*, P. Kaebert, M. Stepanova, T. Poll, M. Siercke†, and S. Ospelkaus

  • Institut für Quantenoptik, Leibniz Universität Hannover, 30167 Hannover, Germany

  • *s.xu@iqo.uni-hannover.de
  • †siercke@iqo.uni-hannover.de
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Phys. Rev. Research 4, L042036 – Published 28 November, 2022

DOI: https://doi.org/10.1103/PhysRevResearch.4.L042036

Abstract

Current dual-frequency magneto-optical traps (MOTs) for ultracold molecules are plagued by sub-Doppler heating effects, making them vastly inferior to standard atomic MOTs. Here we demonstrate theoretically that the sub-Doppler effects in such a MOT can be engineered to provide cooling instead of heating. We give an intuitive picture how to achieve such cooling and show the cooling and trapping force results of the 16-level optical Bloch equations for the case of CaF molecules. From three-dimensional Monte Carlo simulations we estimate the temperature and density of our MOT to be 40μK and 4×108cm−3, respectively, for a molecule number of 1×105. We also extend our idea to the case of atomic MOTs and show that it can be used to produce sub-Doppler forces in these systems that are much more robust against magnetic fields.

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References (24)

  1. E. L. Raab, M. Prentiss, A. Cable, S. Chu, and D. E. Pritchard, Trapping of Neutral Sodium Atoms with Radiation Pressure, Phys. Rev. Lett. 59, 2631 (1987).
  2. C. Monroe, W. Swann, H. Robinson, and C. Wieman, Very Cold Trapped Atoms in a Vapor Cell, Phys. Rev. Lett. 65, 1571 (1990).
  3. P. D. Lett, R. N. Watts, C. I. Westbrook, W. D. Phillips, P. L. Gould, and H. J. Metcalf, Observation of Atoms Laser Cooled below the Doppler Limit, Phys. Rev. Lett. 61, 169 (1988).
  4. J. Dalibard and C. Cohen-Tannoudji, Laser cooling below the Doppler limit by polarization gradients: simple theoretical models, J. Opt. Soc. Am. B 6, 2023 (1989).
  5. D. S. Weiss, E. Riis, Y. Shevy, P. J. Ungar, and S. Chu, Optical molasses and multilevel atoms: experiment, J. Opt. Soc. Am. B 6, 2072 (1989).
  6. S. Truppe, H. J. Williams, M. Hambach, L. Caldwell, N. J. Fitch, E. A. Hinds, B. E. Sauer, and M. R. Tarbutt, Molecules cooled below the doppler limit, Nat. Phys. 13, 1173 (2017).
  7. L. Anderegg, B. L. Augenbraun, Y. Bao, S. Burchesky, L. W. Cheuk, W. Ketterle, and J. M. Doyle, Laser cooling of optically trapped molecules, Nat. Phys. 14, 890 (2018).
  8. S. Ding, Y. Wu, I. A. Finneran, J. J. Burau, and J. Ye, Sub-Doppler Cooling and Compressed Trapping of YO Molecules at μK Temperatures, Phys. Rev. X 10, 021049 (2020).
  9. H. F. Hess, Evaporative cooling of magnetically trapped and compressed spin-polarized hydrogen, Phys. Rev. B 34, 3476 (1986).
  10. M. H. Anderson, J. R. Ensher, M. R. Matthews, C. E. Wieman, and E. A. Cornell, Observation of Bose-Einstein condensation in a dilute atomic vapor, Science 269, 198 (1995).
  11. K. B. Davis, M. O. Mewes, M. R. Andrews, N. J. van Druten, D. S. Durfee, D. M. Kurn, and W. Ketterle, Bose-Einstein Condensation in a Gas of Sodium Atoms, Phys. Rev. Lett. 75, 3969 (1995).
  12. W. Ketterle and N.J. Van Druten, Evaporative Cooling of Trapped Atoms (Academic Press, 1996), pp. 181–236
  13. K. N. Jarvis, J. A. Devlin, T. E. Wall, B. E. Sauer, and M. R. Tarbutt, Blue-Detuned Magneto-Optical Trap, Phys. Rev. Lett. 120, 083201 (2018).
  14. C. J Cooper, G. Hillenbrand, J. Rink, C. G Townsend, K. Zetie, and C. J Foot, The temperature of atoms in a magneto-optical trap, Europhys. Lett. 28, 397 (1994).
  15. H. J. Williams, S. Truppe, M. Hambach, L. Caldwell, N. J. Fitch, E. A. Hinds, B. E. Sauer, and M. R. Tarbutt, Characteristics of a magneto-optical trap of molecules, New J. Phys. 19, 113035 (2017).
  16. J. F. Barry, D. J. McCarron, E. B. Norrgard, M. H. Steinecker, and D. DeMille, Magneto-optical trapping of a diatomic molecule, Nature (London) 512, 286 (2014).
  17. A. L. Collopy, S. Ding, Y. Wu, I. A. Finneran, L. Anderegg, B. L. Augenbraun, J. M. Doyle, and J. Ye, 3D Magneto-Optical Trap of Yttrium Monoxide, Phys. Rev. Lett. 121, 213201 (2018).
  18. L. Anderegg, B. L. Augenbraun, E. Chae, B. Hemmerling, N. R. Hutzler, A. Ravi, A. Collopy, J. Ye, W. Ketterle, and J. M. Doyle, Radio Frequency Magneto-Optical Trapping of CaF with High Density, Phys. Rev. Lett. 119, 103201 (2017).
  19. A. M. L. Oien, I. T. McKinnie, P. J. Manson, W. J. Sandle, and D. M. Warrington, Cooling mechanisms in the sodium type-ii magneto-optical trap, Phys. Rev. A 55, 4621 (1997).
  20. M. R. Tarbutt and T. C. Steimle, Modeling magneto-optical trapping of caf molecules, Phys. Rev. A 92, 053401 (2015).
  21. J. A. Devlin and M. R. Tarbutt, Three-dimensional doppler, polarization-gradient, and magneto-optical forces for atoms and molecules with dark states, New J. Phys. 18, 123017 (2016).
  22. J. A. Devlin and M. R. Tarbutt, Laser cooling and magneto-optical trapping of molecules analyzed using optical bloch equations and the fokker-planck-kramers equation, Phys. Rev. A 98, 063415 (2018).
  23. B. Piest, V. Vollenkemper, J. Böhm, A. Herbst, and E. M. Rasel, Red- and blue-detuned magneto-optical trapping with liquid crystal variable retarders, Rev. Sci. Instrum. 93, 023202 (2022).
  24. H. J. Williams, L. Caldwell, N. J. Fitch, S. Truppe, J. Rodewald, E. A. Hinds, B. E. Sauer, and M. R. Tarbutt, Magnetic Trapping and Coherent Control of Laser-Cooled Molecules, Phys. Rev. Lett. 120, 163201 (2018).

Outline

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Phys. Rev. Research 4, L042036– Published 28 November, 2022
  • Received 11 April 2022
  • Accepted 26 October 2022
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