Abstract
Laser cooling and trapping1,2, and magneto-optical trapping methods in particular2, have enabled groundbreaking advances in science, including BoseâEinstein condensation3,4,5, quantum computation with neutral atoms6,7 and high-precision optical clocks8. Recently, magneto-optical traps (MOTs) of diatomic molecules have been demonstrated9,10,11,12, providing access to research in quantum simulation13 and searches for physics beyond the standard model14. Compared with diatomic molecules, polyatomic molecules have distinct rotational and vibrational degrees of freedom that promise a variety of transformational possibilities. For example, ultracold polyatomic molecules would be uniquely suited to applications in quantum computation and simulation15,16,17, ultracold collisions18, quantum chemistry19 and beyond-the-standard-model searches20,21. However, the complexity of these molecules has so far precluded the realization of MOTs for polyatomic species. Here we demonstrate magneto-optical trapping of a polyatomic molecule, calcium monohydroxide (CaOH). After trapping, the molecules are laser cooled in a blue-detuned optical molasses to a temperature of 110âμK, which is below the Doppler cooling limit. The temperatures and densities achieved here make CaOH a viable candidate for a wide variety of quantum science applications, including quantum simulation and computation using optical tweezer arrays15,17,22,23. This work also suggests that laser cooling and magneto-optical trapping of many other polyatomic species24,25,26,27 will be both feasible and practical.
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The data that support the findings of this study are available from the corresponding author on reasonable request. Source data are provided with this paper.
References
Phillips, W. D. Nobel lecture: Laser cooling and trapping of neutral atoms. Rev. Mod. Phys. 70, 721â741 (1998).
Chu, S. Nobel lecture: The manipulation of neutral particles. Rev. Mod. Phys. 70, 685â706 (1998).
Cornell, E. A. & Wieman, C. E. Nobel lecture: BoseâEinstein condensation in a dilute gas, the first 70 years and some recent experiments. Rev. Mod. Phys. 74, 875â893 (2002).
Anderson, M. H., Ensher, J. R., Matthews, M. R., Wieman, C. E. & Cornell, E. A. Observation of BoseâEinstein condensation in a dilute atomic vapor. Science 269, 198â201 (1995).
Davis, K. B. et al. BoseâEinstein condensation in a gas of sodium atoms. Phys. Rev. Lett. 75, 3969â3973 (1995).
Bernien, H. et al. Probing many-body dynamics on a 51-atom quantum simulator. Nature 551, 579â584 (2017).
Levine, H. et al. Parallel implementation of high-fidelity multiqubit gates with neutral atoms. Phys. Rev. Lett. 123, 170503 (2019).
Ludlow, A. D., Boyd, M. M., Ye, J., Peik, E. & Schmidt, P. O. Optical atomic clocks. Rev. Mod. Phys. 87, 637â701 (2015).
Barry, J. F., McCarron, D., Norrgard, E., Steinecker, M. & DeMille, D. Magneto-optical trapping of a diatomic molecule. Nature 512, 286â289 (2014).
Truppe, S. et al. Molecules cooled below the Doppler limit. Nat. Phys. 13, 1173â1176 (2017).
Anderegg, L. et al. Radio frequency magneto-optical trapping of CaF with high density. Phys. Rev. Lett. 119, 103201 (2017).
Collopy, A. L. et al. 3D magneto-optical trap of yttrium monoxide. Phys. Rev. Lett. 121, 213201 (2018).
Micheli, A., Brennen, G. & Zoller, P. A toolbox for lattice-spin models with polar molecules. Nat. Phys. 2, 341â347 (2006).
Safronova, M. S. et al. Search for new physics with atoms and molecules. Rev. Mod. Phys. 90, 025008 (2018).
Yu, P., Cheuk, L. W., Kozyryev, I. & Doyle, J. M. A scalable quantum computing platform using symmetric-top molecules. New J. Phys. 21, 093049 (2019).
Wall, M. L., Maeda, K. & Carr, L. D. Simulating quantum magnets with symmetric top molecules. Ann. Phys. 525, 845â865 (2013).
Wall, M., Maeda, K. & Carr, L. D. Realizing unconventional quantum magnetism with symmetric top molecules. New J. Phys. 17, 025001 (2015).
AugustoviÄová, L. D. & Bohn, J. L. Ultracold collisions of polyatomic molecules: CaOH. New J. Phys. 21, 103022 (2019).
Heazlewood, B. R. & Softley, T. P. Towards chemistry at absolute zero. Nat. Rev. Chem. 5, 125â140 (2021).
Kozyryev, I. & Hutzler, N. R. Precision measurement of time-reversal symmetry violation with laser-cooled polyatomic molecules. Phys. Rev. Lett. 119, 133002 (2017).
Kozyryev, I., Lasner, Z. & Doyle, J. M. Enhanced sensitivity to ultralight bosonic dark matter in the spectra of the linear radical SrOH. Phys. Rev. A 103, 043313 (2021).
Anderegg, L. et al. An optical tweezer array of ultracold molecules. Science 365, 1156â1158 (2019).
Zhang, J. T. et al. An optical tweezer array of ground-state polar molecules. Quantum Sci. Technol. 7, 035006 (2022).
Isaev, T. A. & Berger, R. Polyatomic candidates for cooling of molecules with lasers from simple theoretical concepts. Phys. Rev. Lett. 116, 063006 (2016).
Kozyryev, I., Baum, L., Matsuda, K. & Doyle, J. M. Proposal for laser cooling of complex polyatomic molecules. ChemPhysChem 17, 3641â3648 (2016).
Augenbraun, B. L., Doyle, J. M., Zelevinsky, T. & Kozyryev, I. Molecular asymmetry and optical cycling: laser cooling asymmetric top molecules. Phys. Rev. X 10, 031022 (2020).
Dickerson, C. E. et al. FranckâCondon tuning of optical cycling centers by organic functionalization. Phys. Rev. Lett. 126, 123002 (2021).
Liu, Y. et al. Magnetic trapping of cold methyl radicals. Phys Rev. Lett. 118, 093201 (2017).
Zeppenfeld, M. et al. Sisyphus cooling of electrically trapped polyatomic molecules. Nature 491, 570â573 (2012).
Prehn, A., Ibrügger, M., Glöckner, R., Rempe, G. & Zeppenfeld, M. Optoelectrical cooling of polar molecules to submillikelvin temperatures. Phys. Rev. Lett. 116, 063005 (2016).
Kozyryev, I. et al. Sisyphus laser cooling of a polyatomic molecule. Phys. Rev. Lett. 118, 173201 (2017).
Baum, L. et al. 1D magneto-optical trap of polyatomic molecules. Phys. Rev. Lett. 124, 133201 (2020).
Augenbraun, B. L. et al. Laser-cooled polyatomic molecules for improved electron electric dipole moment searches. New J. Phys. 22, 022003 (2020).
Mitra, D. et al. Direct laser cooling of a symmetric top molecule. Science 369, 1366â1369 (2020).
Cheuk, L. W. et al. λ-enhanced imaging of molecules in an optical trap. Phys. Rev. Lett. 121, 083201 (2018).
Caldwell, L. et al. Deep laser cooling and efficient magnetic compression of molecules. Phys. Rev. Lett. 123, 033202 (2019).
Langin, T. K., Jorapur, V., Zhu, Y., Wang, Q. & DeMille, D. Polarization enhanced deep optical dipole trapping of Î-cooled polar molecules. Phys. Rev. Lett. 127, 163201 (2021).
Wu, Y., Burau, J. J., Mehling, K., Ye, J. & Ding, S. High phase-space density of laser-cooled molecules in an optical lattice. Phys. Rev. Lett. 127, 263201 (2021).
Anderegg, L. et al. Laser cooling of optically trapped molecules. Nat. Phys. 14, 890â893 (2018).
Hutzler, N. R., Lu, H.-I. & Doyle, J. M. The buffer gas beam: an intense, cold, and slow source for atoms and molecules. Chem. Rev. 112, 4803â4827 (2012).
Jadbabaie, A., Pilgram, N. H., Klos, J., Kotochigova, S. & Hutzler, N. R. Enhanced molecular yield from a cryogenic buffer gas beam source via excited state chemistry. New J. Phys. 22, 022002 (2020).
Zhu, M., Oates, C. W. & Hall, J. L. Continuous high-flux monovelocity atomic beam based on a broadband laser-cooling technique. Phys. Rev. Lett. 67, 46â49 (1991).
Barry, J. F., Shuman, E., Norrgard, E. & DeMille, D. Laser radiation pressure slowing of a molecular beam. Phys. Rev. Lett. 108, 103002 (2012).
Yeo, M. et al. Rotational state microwave mixing for laser cooling of complex diatomic molecules. Phys. Rev. Lett. 114, 223003 (2015).
Hemmerling, B. et al. Laser slowing of CaF molecules to near the capture velocity of a molecular mot. J. Phys. B 49, 174001 (2016).
Truppe, S. et al. An intense, cold, velocity-controlled molecular beam by frequency-chirped laser slowing. New J. Phys. 19, 022001 (2017).
Baum, L. et al. Establishing a nearly closed cycling transition in a polyatomic molecule. Phys. Rev. A 103, 043111 (2021).
Zhang, C. et al. Accurate prediction and measurement of vibronic branching ratios for laser cooling linear polyatomic molecules. J. Chem. Phys. 155, 091101 (2021).
Steinecker, M. H., McCarron, D. J., Zhu, Y. & DeMille, D. Improved radio-frequency magneto-optical trap of srf molecules. ChemPhysChem 17, 3664â3669 (2016).
Berkeland, D. J. & Boshier, M. G. Destabilization of dark states and optical spectroscopy in Zeeman-degenerate atomic systems. Phys. Rev. A 65, 033413 (2002).
Tarbutt, M. Magneto-optical trapping forces for atoms and molecules with complex level structures. New J. Phys. 17, 015007 (2015).
Hummon, M. T. et al. 2D magneto-optical trapping of diatomic molecules. Phys. Rev. Lett. 110, 143001 (2013).
Norrgard, E., McCarron, D., Steinecker, M., Tarbutt, M. & DeMille, D. Submillikelvin dipolar molecules in a radio-frequency magneto-optical trap. Phys. Rev. Lett. 116, 063004 (2016).
Williams, H. et al. Characteristics of a magneto-optical trap of molecules. New J. Phys. 19, 113035 (2017).
Devlin, J. A. & Tarbutt, M. R. Three-dimensional Doppler, polarization-gradient, and magneto-optical forces for atoms and molecules with dark states. New J. Phys. 18, 123017 (2016).
Lim, J. et al. Laser cooled YbF molecules for measuring the electronâs electric dipole moment. Phys. Rev. Lett. 120, 123201 (2018).
Devlin, J. A. & Tarbutt, M. R. Laser cooling and magneto-optical trapping of molecules analyzed using optical Bloch equations and the FokkerâPlanckâKramers equation. Phys. Rev. A 98, 063415 (2018).
Burchesky, S. et al. Rotational coherence times of polar molecules in optical tweezers. Phys. Rev. Lett. 127, 123202 (2021).
Wall, M. L., Hazzard, K. R. A. & Rey, A. M. in From Atomic to Mesoscale: The Role of Quantum Coherence in Systems of Various Complexities (eds Malinovskaya, S. & Novikova, I.) Ch. 1 (World Scientific, 2015).
Dickerson, C. E. et al. Optical cycling functionalization of arenes. J. Phys. Chem. Lett. 12, 3989â3995 (2021).
Augenbraun, B. L. Methods for Direct Laser Cooling of Polyatomic Molecules. PhD thesis, Harvard University (2021).
Oberlander, M. D. & Parson, J. M. Laser excited fluorescence study of reactions of excited Ca and Sr with water and alcohols: product selectivity and energy disposal. J. Chem. Phys. 105, 5806â5816 (1996).
Lu, H.-I., Rasmussen, J., Wright, M. J., Patterson, D. & Doyle, J. M. A cold and slow molecular beam. Phys. Chem. Chem. Phys. 13, 18986â18990 (2011).
Acknowledgements
We acknowledge B. L. Augenbraun and Y. Bao for discussions, and thank S. Kotochigova and J. KÅos for providing theoretical insight into the CaOH chemical enhancement. This work was supported by the AFOSR and the NSF. N.B.V. acknowledges support from the NDSEG fellowship, and L.A. acknowledges support from the HQI.
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N.B.V., C.H., L.A., P.R., A.W. and D.M. designed and assembled the apparatus, discussed experimental protocols and performed the experiment. N.B.V., C.H. and L.A. analysed the data. J.M.D. supervised all work and contributed to setting the direction of the experiment, as well as the design and development of the experimental apparatus, methods and analysis of data. All authors discussed the results and contributed to the manuscript.
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Vilas, N.B., Hallas, C., Anderegg, L. et al. Magneto-optical trapping and sub-Doppler cooling of a polyatomic molecule. Nature 606, 70â74 (2022). https://doi.org/10.1038/s41586-022-04620-5
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DOI: https://doi.org/10.1038/s41586-022-04620-5
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