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Observation of Bose–Einstein condensation of dipolar molecules

Nature volume 631, pages 289–293 (2024)Cite this article

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Abstract

Ensembles of particles governed by quantum mechanical laws exhibit intriguing emergent behaviour. Atomic quantum gases1,2, liquid helium3,4 and electrons in quantum materials5,6,7 all exhibit distinct properties because of their composition and interactions. Quantum degenerate samples of ultracold dipolar molecules promise the realization of new phases of matter and new avenues for quantum simulation8 and quantum computation9. However, rapid losses10, even when reduced through collisional shielding techniques11,12,13, have so far prevented evaporative cooling to a Bose–Einstein condensate (BEC). Here we report on the realization of a BEC of dipolar molecules. By strongly suppressing two- and three-body losses via enhanced collisional shielding, we evaporatively cool sodium–caesium molecules to quantum degeneracy and cross the phase transition to a BEC. The BEC reveals itself by a bimodal distribution when the phase-space density exceeds 1. BECs with a condensate fraction of 60(10)% and a temperature of 6(2) nK are created and found to be stable with a lifetime close to 2 s. This work opens the door to the exploration of dipolar quantum matter in regimes that have been inaccessible so far, promising the creation of exotic dipolar droplets14, self-organized crystal phases15 and dipolar spin liquids in optical lattices16.

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Fig. 1: BEC of dipolar NaCs molecules enabled by microwave shielding.
Fig. 2: Formation of the molecular BEC.
Fig. 3: Evaporative cooling of NaCs molecules to quantum degeneracy.
Fig. 4: Time-of-flight expansion.
Fig. 5: BEC lifetime.

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Data availability

The experimental data that support the findings of this study are available from the corresponding author upon reasonable request. Source data are provided with this paper.

Code availability

All relevant codes are available from the corresponding author upon reasonable request.

References

  1. Anderson, M. H., Ensher, J. R., Matthews, M. R., Wieman, C. E. & Cornell, E. A. Observation of Bose-Einstein condensation in a dilute atomic vapor. Science 269, 198–201 (1995).

    Article  ADS  CAS  PubMed  Google Scholar 

  2. Davis, K. B. et al. Bose-Einstein condensation in a gas of sodium atoms. Phys. Rev. Lett. 75, 3969–3973 (1995).

    Article  ADS  CAS  PubMed  Google Scholar 

  3. Kapitza, P. Viscosity of liquid helium below the λ-point. Nature 141, 74 (1938).

    Article  ADS  CAS  Google Scholar 

  4. Allen, J. F. & Misener, A. Flow of liquid helium II. Nature 141, 75 (1938).

    Article  ADS  CAS  Google Scholar 

  5. Tsui, D. C., Stormer, H. L. & Gossard, A. C. Two-dimensional magnetotransport in the extreme quantum limit. Phys. Rev. Lett. 48, 1559–1562 (1982).

    Article  ADS  CAS  Google Scholar 

  6. Bednorz, J. G. & Müller, K. A. Possible high Tc superconductivity in the Ba–La–Cu–O system. Z. Phys. B Condens. Matter 64, 189–193 (1986).

    Article  ADS  CAS  Google Scholar 

  7. Cao, Y. et al. Unconventional superconductivity in magic-angle graphene superlattices. Nature 556, 43–50 (2018).

    Article  ADS  CAS  PubMed  Google Scholar 

  8. Micheli, A., Brennen, G. & Zoller, P. A toolbox for lattice-spin models with polar molecules. Nat. Phys. 2, 341–347 (2006).

    Article  CAS  Google Scholar 

  9. DeMille, D. Quantum computation with trapped polar molecules. Phys. Rev. Lett. 88, 067901 (2002).

    Article  ADS  CAS  PubMed  Google Scholar 

  10. Ospelkaus, S. et al. Quantum-state controlled chemical reactions of ultracold potassium-rubidium molecules. Science 327, 853–857 (2010).

    Article  ADS  CAS  PubMed  Google Scholar 

  11. Valtolina, G. et al. Dipolar evaporation of reactive molecules to below the Fermi temperature. Nature 588, 239–243 (2020).

    Article  ADS  CAS  PubMed  PubMed Central  Google Scholar 

  12. Matsuda, K. et al. Resonant collisional shielding of reactive molecules using electric fields. Science 370, 1324–1327 (2020).

    Article  ADS  CAS  PubMed  Google Scholar 

  13. Anderegg, L. et al. Observation of microwave shielding of ultracold molecules. Science 373, 779–782 (2021).

    Article  ADS  CAS  PubMed  Google Scholar 

  14. Schmidt, M., Lassablière, L., Quéméner, G. & Langen, T. Self-bound dipolar droplets and supersolids in molecular Bose-Einstein condensates. Phys. Rev. Res. 4, 013235 (2022).

    Article  CAS  Google Scholar 

  15. Büchler, H. P. et al. Strongly correlated 2D quantum phases with cold polar molecules: controlling the shape of the interaction potential. Phys. Rev. Lett. 98, 060404 (2007).

    Article  ADS  PubMed  Google Scholar 

  16. Yao, N. Y., Zaletel, M. P., Stamper-Kurn, D. M. & Vishwanath, A. A quantum dipolar spin liquid. Nat. Phys. 14, 405–410 (2018).

    Article  CAS  Google Scholar 

  17. Inouye, S. et al. Observation of feshbach resonances in a bose–einstein condensate. Nature 392, 151–154 (1998).

    Article  ADS  CAS  Google Scholar 

  18. Greiner, M., Mandel, O., Esslinger, T., Hänsch, T. W. & Bloch, I. Quantum phase transition from a superfluid to a Mott insulator in a gas of ultracold atoms. Nature 415, 39–44 (2002).

    Article  ADS  CAS  PubMed  Google Scholar 

  19. Zwerger, W. The BCS-BEC Crossover and the Unitary Fermi Gas Lecture Notes in Physics, Vol. 836 (Springer Science & Business Media, 2011).

  20. Gross, C. & Bloch, I. Quantum simulations with ultracold atoms in optical lattices. Science 357, 995–1001 (2017).

    Article  ADS  CAS  PubMed  Google Scholar 

  21. Chomaz, L. et al. Dipolar physics: a review of experiments with magnetic quantum gases. Rep. Prog. Phys. 86, 026401 (2022).

    Article  ADS  Google Scholar 

  22. Lahaye, T. et al. Strong dipolar effects in a quantum ferrofluid. Nature 448, 672–675 (2007).

    Article  ADS  CAS  PubMed  Google Scholar 

  23. Kadau, H. et al. Observing the Rosensweig instability of a quantum ferrofluid. Nature 530, 194–197 (2016).

    Article  ADS  CAS  PubMed  Google Scholar 

  24. Chomaz, L. et al. Quantum-fluctuation-driven crossover from a dilute Bose-Einstein condensate to a macrodroplet in a dipolar quantum fluid. Phys. Rev. X 6, 041039 (2016).

    Google Scholar 

  25. Böttcher, F. et al. Transient supersolid properties in an array of dipolar quantum droplets. Phys. Rev. X 9, 011051 (2019).

    Google Scholar 

  26. Chomaz, L. et al. Long-lived and transient supersolid behaviors in dipolar quantum gases. Phys. Rev. X 9, 021012 (2019).

    CAS  Google Scholar 

  27. Tanzi, L. et al. Observation of a dipolar quantum gas with metastable supersolid properties. Phys. Rev. Lett. 122, 130405 (2019).

    Article  ADS  CAS  PubMed  Google Scholar 

  28. Wilks, J. The Properties of Liquid and Solid Helium (Clarendon, 1967).

  29. Bardeen, J., Cooper, L. N. & Schrieffer, J. R. Theory of superconductivity. Phys. Rev. 108, 1175–1204 (1957).

    Article  ADS  MathSciNet  CAS  Google Scholar 

  30. Laughlin, R. B. Anomalous quantum hall effect: an incompressible quantum fluid with fractionally charged excitations. Phys. Rev. Lett. 50, 1395–1398 (1983).

    Article  ADS  Google Scholar 

  31. Baranov, M. A., Dalmonte, M., Pupillo, G. & Zoller, P. Condensed matter theory of dipolar quantum gases. Chem. Rev. 112, 5012–5061 (2012).

    Article  CAS  PubMed  Google Scholar 

  32. Pollet, L., Picon, J., Büchler, H. & Troyer, M. Supersolid phase with cold polar molecules on a triangular lattice. Phys. Rev. Lett. 104, 125302 (2010).

    Article  ADS  CAS  PubMed  Google Scholar 

  33. Góral, K., Santos, L. & Lewenstein, M. Quantum phases of dipolar bosons in optical lattices. Phys. Rev. Lett. 88, 170406 (2002).

    Article  ADS  PubMed  Google Scholar 

  34. Ni, K.-K. et al. A high phase-space-density gas of polar molecules. Science 322, 231–235 (2008).

    Article  ADS  CAS  PubMed  Google Scholar 

  35. Żuchowski, P. S. & Hutson, J. M. Reactions of ultracold alkali-metal dimers. Phys. Rev. A 81, 060703 (2010).

    Article  ADS  Google Scholar 

  36. Takekoshi, T. et al. Ultracold dense samples of dipolar RbCs molecules in the rovibrational and hyperfine ground state. Phys. Rev. Lett. 113, 205301 (2014).

    Article  ADS  PubMed  Google Scholar 

  37. Molony, P. K. et al. Creation of ultracold 87Rb133Cs molecules in the rovibrational ground state. Phys. Rev. Lett. 113, 255301 (2014).

    Article  ADS  PubMed  Google Scholar 

  38. Park, J. W., Will, S. A. & Zwierlein, M. W. Ultracold dipolar gas of fermionic 23Na40K molecules in their absolute ground state. Phys. Rev. Lett. 114, 205302 (2015).

    Article  ADS  PubMed  Google Scholar 

  39. Ye, X., Guo, M., González-Martínez, M. L., Quéméner, G. & Wang, D. Collisions of ultracold 23Na87Rb molecules with controlled chemical reactivities. Sci. Adv. 4, eaaq0083 (2018).

    Article  ADS  PubMed  PubMed Central  Google Scholar 

  40. Gregory, P. D. et al. Sticky collisions of ultracold RbCs molecules. Nat. Commun. 10, 3104 (2019).

    Article  ADS  PubMed  PubMed Central  Google Scholar 

  41. Bause, R. et al. Collisions of ultracold molecules in bright and dark optical dipole traps. Phys. Rev. Res. 3, 033013 (2021).

    Article  CAS  Google Scholar 

  42. De Marco, L. et al. A degenerate fermi gas of polar molecules. Science 363, 853–856 (2019).

    Article  ADS  PubMed  Google Scholar 

  43. Duda, M. et al. Transition from a polaronic condensate to a degenerate fermi gas of heteronuclear molecules. Nat. Phys. 19, 720–725 (2023).

    Article  CAS  Google Scholar 

  44. Cooper, N. & Shlyapnikov, G. V. Stable topological superfluid phase of ultracold polar fermionic molecules. Phys. Rev. Lett. 103, 155302 (2009).

    Article  ADS  CAS  PubMed  Google Scholar 

  45. Micheli, A. et al. Universal rates for reactive ultracold polar molecules in reduced dimensions. Phys. Rev. Lett. 105, 073202 (2010).

    Article  ADS  PubMed  Google Scholar 

  46. Lassablière, L. & Quéméner, G. Controlling the scattering length of ultracold dipolar molecules. Phys. Rev. Lett. 121, 163402 (2018).

    Article  ADS  PubMed  Google Scholar 

  47. Karman, T. & Hutson, J. M. Microwave shielding of ultracold polar molecules. Phys. Rev. Lett. 121, 163401 (2018).

    Article  ADS  CAS  PubMed  Google Scholar 

  48. Schindewolf, A. et al. Evaporation of microwave-shielded polar molecules to quantum degeneracy. Nature 607, 677–681 (2022).

    Article  ADS  CAS  PubMed  PubMed Central  Google Scholar 

  49. Julienne, P. S., Hanna, T. M. & Idziaszek, Z. Universal ultracold collision rates for polar molecules of two alkali-metal atoms. Phys. Chem. Chem. Phys. 13, 19114–19124 (2011).

    Article  CAS  PubMed  Google Scholar 

  50. Bigagli, N. et al. Collisionally stable gas of bosonic dipolar ground-state molecules. Nat. Phys. 19, 1579–1584 (2023).

    Article  CAS  Google Scholar 

  51. Lin, J. et al. Microwave shielding of bosonic NaRb molecules. Phys. Rev. X 13, 031032 (2023).

    CAS  Google Scholar 

  52. Avdeenkov, A. & Bohn, J. L. Linking ultracold polar molecules. Phys. Rev. Lett. 90, 043006 (2003).

    Article  ADS  CAS  PubMed  Google Scholar 

  53. Chen, X.-Y. et al. Ultracold field-linked tetratomic molecules. Nature 626, 283–287 (2024).

    Article  ADS  CAS  PubMed  PubMed Central  Google Scholar 

  54. Micheli, A., Pupillo, G., Büchler, H. & Zoller, P. Cold polar molecules in two-dimensional traps: tailoring interactions with external fields for novel quantum phases. Phys. Rev. A 76, 043604 (2007).

    Article  ADS  Google Scholar 

  55. Gorshkov, A. V. et al. Suppression of inelastic collisions between polar molecules with a repulsive shield. Phys. Rev. Lett. 101, 073201 (2008).

    Article  ADS  CAS  PubMed  Google Scholar 

  56. Son, H., Park, J. J., Ketterle, W. & Jamison, A. O. Collisional cooling of ultracold molecules. Nature 580, 197–200 (2020).

    Article  ADS  CAS  PubMed  Google Scholar 

  57. Li, J.-R. et al. Tuning of dipolar interactions and evaporative cooling in a three-dimensional molecular quantum gas. Nat. Phys. 17, 1144–1148 (2021).

    Article  CAS  Google Scholar 

  58. Mewes, M.-O. et al. Bose-Einstein condensation in a tightly confining dc magnetic trap. Phys. Rev. Lett. 77, 416–419 (1996).

    Article  ADS  CAS  PubMed  Google Scholar 

  59. Dagdigian, P. J. & Wharton, L. Molecular beam electric deflection and resonance spectroscopy of the heteronuclear alkali dimers: 39K7Li, Rb7Li, 39K23Na, Rb23Na, and 133Cs23Na. J. Chem. Phys. 57, 1487–1496 (1972).

    Article  ADS  CAS  Google Scholar 

  60. Capogrosso-Sansone, B., Trefzger, C., Lewenstein, M., Zoller, P. & Pupillo, G. Quantum phases of cold polar molecules in 2D optical lattices. Phys. Rev. Lett. 104, 125301 (2010).

    Article  ADS  CAS  PubMed  Google Scholar 

  61. Gorshkov, A. V. et al. Tunable superfluidity and quantum magnetism with ultracold polar molecules. Phys. Rev. Lett. 107, 115301 (2011).

    Article  ADS  PubMed  Google Scholar 

  62. Manmana, S. R., Stoudenmire, E., Hazzard, K. R., Rey, A. M. & Gorshkov, A. V. Topological phases in ultracold polar-molecule quantum magnets. Phys. Rev. B 87, 081106 (2013).

    Article  ADS  Google Scholar 

  63. Büchler, H., Micheli, A. & Zoller, P. Three-body interactions with cold polar molecules. Nat. Phys. 3, 726–731 (2007).

    Article  Google Scholar 

  64. Warner, C. et al. Overlapping Bose-Einstein condensates of 23Na and 133Cs. Phys. Rev. A 104, 033302 (2021).

    Article  ADS  CAS  Google Scholar 

  65. Lam, A. Z. et al. High phase-space density gas of NaCs Feshbach molecules. Phys. Rev. Res. 4, L022019 (2022).

    Article  CAS  Google Scholar 

  66. Stevenson, I. et al. Ultracold gas of dipolar NaCs ground state molecules. Phys. Rev. Lett. 130, 113022 (2023).

    Article  ADS  Google Scholar 

  67. Warner, C. et al. Efficient pathway to nacs ground state molecules. New J. Phys. 25, 053036 (2023).

    Article  ADS  Google Scholar 

  68. Yuan, W. et al. A planar cloverleaf antenna for circularly polarized microwave fields in atomic and molecular physics experiments. Rev. Sci. Instrum. 94, 123201 (2023).

    Article  ADS  CAS  PubMed  Google Scholar 

  69. Dalfovo, F., Giorgini, S., Pitaevskii, L. P. & Stringari, S. Theory of Bose-Einstein condensation in trapped gases. Rev. Mod. Phys. 71, 463–512 (1999).

    Article  ADS  CAS  Google Scholar 

  70. Söding, J. et al. Three-body decay of a rubidium Bose–Einstein condensate. Appl. Phys. B 69, 257–261 (1999).

    Article  ADS  Google Scholar 

  71. Karman, T. & Hutson, J. M. Microwave shielding of ultracold polar molecules with imperfectly circular polarization. Phys. Rev. A 100, 052704 (2019).

    Article  ADS  CAS  Google Scholar 

  72. Colbert, D. T. & Miller, W. H. A novel discrete variable representation for quantum mechanical reactive scattering via the S-matrix Kohn method. J. Chem. Phys. 96, 1982–1991 (1992).

    Article  ADS  CAS  Google Scholar 

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Acknowledgements

We thank C. Greene, A. Elkamshishy and S. Singh for their discussions and preliminary calculations on the field-linked bound states in the shielding potentials, and R. Wooten, T. Yefsah and M. Zwierlein for critical reading and helpful comments on the paper. We are grateful to A. Lam and C. Warner for their contributions to the construction of the experimental apparatus. We also thank I. Bloch, T.-L. Ho and V. Vuletić for their discussions. We acknowledge E. Bellingham and H. Kwak for their experimental assistance. We thank Rohde & Schwarz for the loan of equipment. This work was supported by an NSF CAREER Award (award no. 1848466), an ONR DURIP Award (award no. N00014-21-1-2721), a grant from the Gordon and Betty Moore Foundation (award no. GBMF12340) and a Lenfest Junior Faculty Development Grant from Columbia University. W.Y. acknowledges support from the Croucher Foundation. I.S. was supported by the Ernest Kempton Adams Fund. S.W. acknowledges additional support from the Alfred P. Sloan Foundation.

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  1. These authors contributed equally: Niccolò Bigagli, Weijun Yuan, Siwei Zhang

Authors and Affiliations

  1. Department of Physics, Columbia University, New York, NY, USA

    Niccolò Bigagli, Weijun Yuan, Siwei Zhang, Boris Bulatovic, Ian Stevenson & Sebastian Will

  2. Institute for Molecules and Materials, Radboud University, Nijmegen, The Netherlands

    Tijs Karman

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Contributions

All authors contributed substantially to the work presented in this paper. N.B., W.Y., S.Z. and I.S. carried out the experiments and improved the experimental setup. T.K. performed the theoretical calculations. S.W. supervised the study. N.B., I.S. and S.W. wrote the paper. All authors contributed to the development of the experimental concepts, interpretation of the data and reviewed the paper.

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Correspondence to Sebastian Will.

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Nature thanks Lauriane Chomaz, Simon Cornish and the other, anonymous, reviewer(s) for their contribution to the peer review of this work. Peer reviewer reports are available.

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Extended data figures and tables

Extended Data Fig. 1 Microwave setup.

a, Block diagram of the microwave components producing the σ+ field. b, Block diagram of the microwave components producing the π field. MHz-level detunings are omitted from the shown frequencies of the source.

Extended Data Fig. 2 Comparison of fitting models.

Ratio of χ2-values for Gaussian and bimodal fits. The vertical dashed line marks the onset of the phase transition.

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Bigagli, N., Yuan, W., Zhang, S. et al. Observation of Bose–Einstein condensation of dipolar molecules. Nature 631, 289–293 (2024). https://doi.org/10.1038/s41586-024-07492-z

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