- Physical Review Journals
All JournalsPhysics Magazine
Access Provided by Xinjiang University

Physical Review A

Reuse & Permissions

It is not necessary to obtain permission to reuse this article or its components as it is available under the terms of the Creative Commons Attribution 4.0 International license. This license permits unrestricted use, distribution, and reproduction in any medium, provided attribution to the author(s) and the published article's title, journal citation, and DOI are maintained. Please note that some figures may have been included with permission from other third parties. It is your responsibility to obtain the proper permission from the rights holder directly for these figures.

Export citation

Export citation

Choose format for download:

Download Citation
  • Open Access
  • Access by Xinjiang University

Continuous accumulation of cold atoms in an optical cavity

Edward Gheorghita*, Sebastian Wald*, Andrea Pupić, and Onur Hosten†

  • *These authors contributed equally to this work.
  • †Contact author: onur.hosten@ist.ac.at
PDF

Phys. Rev. A 114, 023302 – Published 3 August, 2026

DOI: https://doi.org/10.1103/71f2-sq4p

Abstract

Continuously operating atom-light interfaces represent a key prerequisite for steady-state quantum sensors and efficient quantum processors. Here, we demonstrate continuous accumulation of sub-Doppler-cooled atoms in a shallow intracavity dipole trap, realizing this regime. The key ingredient is a light-shift manipulation that creates spatially varying cooling parameters, enabling efficient capture and accumulation of atoms within a cavity mode. Demonstrated with rubidium atoms, a continuous flux from a source cell is funneled through the magneto-optical trap into the cavity mode, where the atoms are cooled and maintained below 10µK in steady state without time-sequenced operation. We characterize the resulting continuously maintained ensemble of millions of atoms and its collective coupling to the cavity field, establishing a route toward continuously operated cavity-QED systems and long-duration atomic and hybrid quantum sensors.

View figure in article

Physics Subject Headings (PhySH)

Article Text

References (55)

  1. V. M. Schäfer, Z. Niu, J. R. Cline, D. J. Young, E. Y. Song, H. Ritsch, and J. K. Thompson, Continuous recoil-driven lasing and cavity frequency pinning with laser-cooled atoms, Nat. Phys. 21, 902 (2025).
  2. J. R. Cline, V. M. Schäfer, Z. Niu, D. J. Young, T. H. Yoon, and J. K. Thompson, Continuous collective strong coupling of strontium atoms to a high finesse ring cavity, Phys. Rev. Lett. 134, 013403 (2025).
  3. K. Singh, S. Anand, A. Pocklington, J. T. Kemp, and H. Bernien, Dual-element, two-dimensional atom array with continuous-mode operation, Phys. Rev. X 12, 011040 (2022).
  4. C.-C. Chen, R. González Escudero, J. Minář, B. Pasquiou, S. Bennetts, and F. Schreck, Continuous Bose–Einstein condensation, Nature (London) 606, 683 (2022).
  5. J. M. Kwolek and A. T. Black, Continuous sub-Doppler-cooled atomic beam interferometer for inertial sensing, Phys. Rev. Appl. 17, 024061 (2022).
  6. M. Schioppo, R. C. Brown, W. F. McGrew, N. Hinkley, R. J. Fasano, K. Beloy, T. Yoon, G. Milani, D. Nicolodi, J. Sherman, et al., Ultrastable optical clock with two cold-atom ensembles, Nat. Photon. 11, 48 (2017).
  7. H. Krauter, C. A. Muschik, K. Jensen, W. Wasilewski, J. M. Petersen, J. I. Cirac, and E. S. Polzik, Entanglement generated by dissipation and steady state entanglement of two macroscopic objects, Phys. Rev. Lett. 107, 080503 (2011).
  8. J. T. Reilly, S. B. Jäger, J. Cooper, and M. J. Holland, Fully collective superradiant lasing with vanishing sensitivity to cavity length vibrations, Phys. Rev. Lett. 136, 143803 (2026).
  9. T. M. Karg, B. Gouraud, C. T. Ngai, G.-L. Schmid, K. Hammerer, and P. Treutlein, Light-mediated strong coupling between a mechanical oscillator and atomic spins 1 meter apart, Science 369, 174 (2020).
  10. J. A. Muniz, D. Crow, H. Kim, J. M. Kindem, W. B. Cairncross, A. Ryou, T. C. Bohdanowicz, C.-A. Chen, Y. Ji, A. W. M. Jones, et al., Repeated ancilla reuse for logical computation on a neutral atom quantum computer, Phys. Rev. X 15, 041040 (2025).
  11. F. Diorico, A. Zhutov, and O. Hosten, Laser-cavity locking utilizing beam ellipticity: Accessing the 10-7 instability scale relative to cavity linewidth, Optica 11, 26 (2024).
  12. L. Pezze, A. Smerzi, M. K. Oberthaler, R. Schmied, and P. Treutlein, Quantum metrology with nonclassical states of atomic ensembles, Rev. Mod. Phys. 90, 035005 (2018).
  13. S. S. Szigeti, O. Hosten, and S. A. Haine, Improving cold-atom sensors with quantum entanglement: Prospects and challenges, Appl. Phys. Lett. 118, 140501 (2021).
  14. M. Kitagawa and M. Ueda, Squeezed spin states, Phys. Rev. A 47, 5138 (1993).
  15. M. H. Schleier-Smith, I. D. Leroux, and V. Vuletić, Squeezing the collective spin of a dilute atomic ensemble by cavity feedback, Phys. Rev. A 81, 021804(R) (2010).
  16. K. C. Cox, G. P. Greve, J. M. Weiner, and J. K. Thompson, Deterministic squeezed states with collective measurements and feedback, Phys. Rev. Lett. 116, 093602 (2016).
  17. O. Hosten, N. J. Engelsen, R. Krishnakumar, and M. A. Kasevich, Measurement noise 100 times lower than the quantum-projection limit using entangled atoms, Nature (London) 529, 505 (2016).
  18. O. Hosten, R. Krishnakumar, N. J. Engelsen, and M. A. Kasevich, Quantum phase magnification, Science 352, 1552 (2016).
  19. B. K. Malia, Y. Wu, J. Martínez-Rincón, and M. A. Kasevich, Distributed quantum sensing with mode-entangled spin-squeezed atomic states, Nature (London) 612, 661 (2022).
  20. G. P. Greve, C. Luo, B. Wu, and J. K. Thompson, Entanglement-enhanced matter-wave interferometry in a high-finesse cavity, Nature (London) 610, 472 (2022).
  21. C. Cassens, B. Meyer-Hoppe, E. Rasel, and C. Klempt, Entanglement-enhanced atomic gravimeter, Phys. Rev. X 15, 011029 (2025).
  22. A. D. Cronin, J. Schmiedmayer, and D. E. Pritchard, Optics and interferometry with atoms and molecules, Rev. Mod. Phys. 81, 1051 (2009).
  23. C. F. Ockeloen, R. Schmied, M. F. Riedel, and P. Treutlein, Quantum metrology with a scanning probe atom interferometer, Phys. Rev. Lett. 111, 143001 (2013).
  24. A. Peters, K. Y. Chung, and S. Chu, Measurement of gravitational acceleration by dropping atoms, Nature (London) 400, 849 (1999).
  25. M. Kasevich and S. Chu, Atomic interferometry using stimulated Raman transitions, Phys. Rev. Lett. 67, 181 (1991).
  26. A. Aeppli, K. Kim, W. Warfield, M. S. Safronova, and J. Ye, Clock with 8×10−19 systematic uncertainty, Phys. Rev. Lett. 133, 023401 (2024).
  27. E. Pedrozo-Peñafiel, S. Colombo, C. Shu, A. F. Adiyatullin, Z. Li, E. Mendez, B. Braverman, A. Kawasaki, D. Akamatsu, Y. Xiao, et al., Entanglement on an optical atomic-clock transition, Nature (London) 588, 414 (2020).
  28. N. J. Engelsen, Quantum metrology using large ensembles of entangled atoms, Ph.D. thesis, Stanford University, 2016.
  29. D. S. Naik, H. Eneriz-Imaz, M. Carey, T. Freegarde, F. Minardi, B. Battelier, P. Bouyer, and A. Bertoldi, Loading and cooling in an optical trap via hyperfine dark states, Phys. Rev. Res. 2, 013212 (2020).
  30. G. Kuyumjyan, Condensation de Bose-Einstein multiple dans les modes d'ordre supérieurs d'une cavité optique bi-fréquence, Ph.D. thesis, Université de Bordeaux, 2017.
  31. P. Griffin, K. Weatherill, S. MacLeod, R. Potvliege, and C. Adams, Spatially selective loading of an optical lattice by light-shift engineering using an auxiliary laser field, New J. Phys. 8, 11 (2006).
  32. S. Coop, S. Palacios, P. Gomez, Y. N. M. de Escobar, T. Vanderbruggen, and M. W. Mitchell, Floquet theory for atomic light-shift engineering with near-resonant polychromatic fields, Opt. Express 25, 32550 (2017).
  33. S. Palacios, S. Coop, P. Gomez, T. Vanderbruggen, Y. N. M. de Escobar, M. Jasperse, and M. W. Mitchell, Multi-second magnetic coherence in a single domain spinor Bose–Einstein condensate, New J. Phys. 20, 053008 (2018).
  34. T. Vanderbruggen, R. Kohlhaas, A. Bertoldi, S. Bernon, A. Aspect, A. Landragin, and P. Bouyer, Feedback control of trapped coherent atomic ensembles, Phys. Rev. Lett. 110, 210503 (2013).
  35. R. Kohlhaas, A. Bertoldi, E. Cantin, A. Aspect, A. Landragin, and P. Bouyer, Phase locking a clock oscillator to a coherent atomic ensemble, Phys. Rev. X 5, 021011 (2015).
  36. D. Bluvstein, A. A. Geim, S. H. Li, S. J. Evered, J. P. B. Ataides, G. Baranes, A. Gu, T. Manovitz, M. Xu, M. Kalinowski, et al., A fault-tolerant neutral-atom architecture for universal quantum computation, Nature (London) 649, 39 (2026).
  37. H. J. Metcalf and P. Van der Straten, Laser Cooling and Trapping (Springer Science & Business Media, Berlin/Heidelberg, 1999).
  38. B. Arora, M. S. Safronova, and C. W. Clark, Magic wavelengths for the np−ns transitions in alkali-metal atoms, Phys. Rev. A 76, 052509 (2007).
  39. S. Bernon, Trapping and nondemolition measurement of cold atoms in a high-finesse ring cavity, Ph.D. thesis, Ecole Polytechnique, Palaiseau, France, 2011.
  40. J.-P. Brantut, J.-F. Clément, M. R. de Saint Vincent, G. Varoquaux, R. A. Nyman, A. Aspect, T. Bourdel, and P. Bouyer, Light-shift tomography in an optical-dipole trap for neutral atoms, Phys. Rev. A 78, 031401(R) (2008).
  41. C.-Y. Shih and M. S. Chapman, Nondestructive light-shift measurements of single atoms in optical dipole traps, Phys. Rev. A 87, 063408 (2013).
  42. D. A. Steck, Rubidium 87 D line data (2001) http://steck.us/alkalidata.
  43. S. Chu, L. Hollberg, J. E. Bjorkholm, A. Cable, and A. Ashkin, Three-dimensional viscous confinement and cooling of atoms by resonance radiation pressure, Phys. Rev. Lett. 55, 48 (1985).
  44. C. Adams and E. Riis, Laser cooling and trapping of neutral atoms, Prog. Quantum Electron. 21, 1 (1997).
  45. M. S. Safronova and U. I. Safronova, Critically evaluated theoretical energies, lifetimes, hyperfine constants, and multipole polarizabilities in Rb87, Phys. Rev. A 83, 052508 (2011).
  46. K. Hammerer, K. Mølmer, E. S. Polzik, and J. I. Cirac, Light-matter quantum interface, Phys. Rev. A 70, 044304 (2004).
  47. S. J. M. Kuppens, K. L. Corwin, K. W. Miller, T. E. Chupp, and C. E. Wieman, Loading an optical dipole trap, Phys. Rev. A 62, 013406 (2000).
  48. K. Brzozowski, L. Krzemien, J. Zachorowski, and W. Gawlik, Diagnostics and loading of an atomic optical dipole trap, Optica Applicata 40, 557 (2010).
  49. S. Wald, F. Diorico, and O. Hosten, Analog stabilization of an electro-optic I/Q modulator with an auxiliary modulation tone, Appl. Opt. 62, 1 (2023).
  50. R. W. Fox, C. W. Oates, and L. W. Hollberg, 1. Stabilizing diode lasers to high-finesse cavities, in Experimental Methods in the Physical Sciences (Elsevier, New York, 2003), Vol. 40, pp. 1–46.
  51. V. Li, F. Diorico, and O. Hosten, Laser frequency-offset locking at 10-Hz-level instability using hybrid electronic filters, Phys. Rev. Appl. 17, 054031 (2022).
  52. R. K. Raj, D. Bloch, J. J. Snyder, G. Camy, and M. Ducloy, High-frequency optically heterodyned saturation spectroscopy via resonant degenerate four-wave mixing, Phys. Rev. Lett. 44, 1251 (1980).
  53. G. Avila, V. Giordano, V. Candelier, E. de Clercq, G. Theobald, and P. Cerez, State selection in a cesium beam by laser-diode optical pumping, Phys. Rev. A 36, 3719 (1987).
  54. Y.-X. Duan, B. Wang, J.-F. Xiang, Q. Liu, Q.-Z. Qu, D.-S. Lü, and L. Liu, State preparation in a cold atom clock by optical pumping, Chin. Phys. Lett. 34, 073201 (2017).
  55. https://github.com/hostengroup.

Outline

Information

Phys. Rev. A 114, 023302– Published 3 August, 2026
  • Received 16 December 2025
  • Accepted 13 July 2026
Crossmark - Check for updates button
Creative Commons Logo

Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.

Published by the American Physical Society

Sign In to Your Journals Account

Filter

Filter

Article Lookup

Enter a citation