- Physical Review Journals
All JournalsPhysics Magazine

Physical Review Applied

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

Continuous-time ultrahigh-frequency sensing using cold Rydberg atoms

Matt J. Jamieson*, C. Stuart Adams, and Kevin J. Weatherill

Ryan K. Hanley, Natalia Alves, and James Keaveney

  • Infleqtion UK, Oxford Technology Park, Kidlington OX5 1GN, United Kingdom

  • *Contact author: mjjamieson21@gmail.com
PDF

Phys. Rev. Applied 24, 034022 – Published 8 September, 2025

DOI: https://doi.org/10.1103/2vxb-czvz

Abstract

We present a technique for detecting ultrahigh-frequency (UHF) radio fields using a three-photon Rydberg excitation scheme in a continuously laser-cooled sample of 87Rb atoms. By measuring Autler-Townes splitting, we demonstrate resonant detection of UHF fields with frequency range around 500–900 MHz through probing nF→nG transitions, achieving a lowest minimum detectable field of 2.5(6) mV/cm at 899 MHz. We also demonstrate continuous-time detection of a modulated rf signal, with a 3-dB bandwidth of 5.7(4) kHz at a carrier frequency of 899 MHz. Our approach employs atom loss spectroscopy rather than electromagnetically induced transparency , which enables detection while the atomic sample is simultaneously laser-cooled. We investigate this operating regime to determine the feasibility of combining the benefits of reduced thermal dephasing (and subsequent increased sensitivity) of cold atoms with the continuous operation associated with thermal atoms. Our continuous-time detection scheme provides an advantage over existing pulsed cold atom systems as we avoid the slow experimental duty cycles typically associated with replenishing the cold atom ensemble. We characterize the excitation scheme by varying laser detunings and analyze the impact and limitations due to various broadening mechanisms on the detection sensitivity.

View figure in article

Physics Subject Headings (PhySH)

Article Text

References (61)

  1. C. S. Adams, J. D. Pritchard, and J. P. Shaffer, Rydberg atom quantum technologies, J. Phys. B 53, 012002 (2019).
  2. T. F. Gallagher, Rydberg Atoms (Cambridge University Press, Cambridge, 1994).
  3. H. Fan, S. Kumar, J. Sedlacek, H. Kübler, S. Karimkashi, and J. P. Shaffer, Atom based RF electric field sensing, J. Phys. B 48, 202001 (2015).
  4. D. H. Meyer, Z. A. Castillo, K. C. Cox, and P. D. Kunz, Assessment of Rydberg atoms for wideband electric field sensing, J. Phys. B 53, 034001 (2020).
  5. K. C. Cox, D. H. Meyer, F. K. Fatemi, and P. D. Kunz, Quantum-limited atomic receiver in the electrically small regime, Phys. Rev. Lett. 121, 110502 (2018).
  6. P. Padovani, The faint radio sky: radio astronomy becomes mainstream, Astron. Astrophys. Rev. 24, 13 (2016).
  7. J. Ingerski and A. Sapp, in MILCOM 2002. Proceedings (IEEE, Anaheim, CA, USA, 2002), Vol. 1, pp. 642–646.
  8. H. Carreno-Luengo, C. S. Ruf, S. Gleason, and A. Russel, Detection of inland water bodies under dense biomass by CYGNSS, Remote Sens. Environ. 301, 113896 (2024).
  9. M. M. Farhad, A. M. Alam, S. Biswas, M. A. S. Rafi, A. C. Gurbuz, and M. Kurum, SDR-based dual polarized l-band microwave radiometer operating from small UAS platforms, IEEE J. Sel. Top. Appl. Earth Obs. Remote Sens. 17, 6617 (2024).
  10. N. Neji, R. de Lacerda, A. Azoulay, T. Letertre, and O. Outtier, Survey on the future aeronautical communication system and its development for continental communications, IEEE Trans. Veh. Technol. 62, 83 (2013).
  11. S. Orasch, H. Flühr, C. Rihacek, and B. Haindl, in 2024 47th MIPRO ICT and Electronics Convention (MIPRO) (IEEE, Opatija, Croatia, 2024), pp. 195–200.
  12. J. R. Rigley, Aeronautical mobile satellite services: The launching of a new era in mobile communications, Can. J. Electr. Comput. Eng. 17, 175 (1992).
  13. F. Raab, R. Caverly, R. Campbell, M. Eron, J. Hecht, A. Mediano, D. Myer, and J. Walker, HF, VHF, and UHF systems and technology, IEEE Trans. Microwave Theory Tech. 50, 614 (2002).
  14. C. L. Holloway, J. A. Gordon, S. Jefferts, A. Schwarzkopf, D. A. Anderson, S. A. Miller, N. Thaicharoen, and G. Raithel, Broadband Rydberg atom-based electric-field probe for SI-traceable, self-calibrated measurements, IEEE Trans. Antennas Propag. 62, 6169 (2014).
  15. A. K. Mohapatra, T. R. Jackson, and C. S. Adams, Coherent optical detection of highly excited Rydberg states using electromagnetically induced transparency, Phys. Rev. Lett. 98, 113003 (2007).
  16. N. Šibalić, J. Pritchard, C. Adams, and K. Weatherill, ARC: An open-source library for calculating properties of alkali Rydberg atoms, Comput. Phys. Commun. 220, 319 (2017).
  17. D. H. Meyer, K. C. Cox, F. K. Fatemi, and P. D. Kunz, Digital communication with Rydberg atoms and amplitude-modulated microwave fields, Appl. Phys. Lett. 112, 211108 (2018).
  18. J. S. Otto, M. Chilcott, A. B. Deb, and N. Kjaergaard, Distant RF field sensing with a passive Rydberg-atomic transducer, Appl. Phys. Lett. 123, 144003 (2023).
  19. M. Jing, Y. Hu, J. Ma, H. Zhang, L. Zhang, L. Xiao, and S. Jia, Atomic superheterodyne receiver based on microwave-dressed Rydberg spectroscopy, Nat. Phys. 16, 915 (2020).
  20. L. Ma, M. A. Viray, D. A. Anderson, and G. Raithel, Measurement of dc and ac electric fields inside an atomic vapor cell with wall-integrated electrodes, Phys. Rev. Appl. 18, 024001 (2022).
  21. C. L. Holloway, M. T. Simons, J. A. Gordon, P. F. Wilson, C. M. Cooke, D. A. Anderson, and G. Raithel, Atom-based RF electric field metrology: From self-calibrated measurements to subwavelength and near-field imaging, IEEE Trans. Electromagn. Compat. 59, 717 (2017).
  22. E. Paradis, G. Raithel, and D. A. Anderson, Atomic measurements of high-intensity VHF-band radio-frequency fields with a Rydberg vapor-cell detector, Phys. Rev. A 100, 013420 (2019).
  23. D. H. Meyer, P. D. Kunz, and K. C. Cox, Waveguide-coupled Rydberg spectrum analyzer from 0 to 20 GHz, Phys. Rev. Appl. 15, 014053 (2021).
  24. S. M. Bohaichuk, D. Booth, K. Nickerson, H. Tai, and J. P. Shaffer, Origins of Rydberg-atom electrometer transient response and its impact on radio-frequency pulse sensing, Phys. Rev. Appl. 18, 034030 (2022).
  25. T. Minhas, in Quantum Sensing, Imaging, and Precision Metrology II (SPIE, San Francisco, CA, USA, 2024), Vol. 12912, p. 129120B.
  26. Z. Song, H. Liu, X. Liu, W. Zhang, H. Zou, J. Zhang, and J. Qu, Rydberg-atom-based digital communication using a continuously tunable radio-frequency carrier, Opt. Express 27, 8848 (2019).
  27. A. K. Mohapatra, M. G. Bason, B. Butscher, K. J. Weatherill, and C. S. Adams, A giant electro-optic effect using polarizable dark states, Nat. Phys. 4, 890 (2008).
  28. A. P. Rotunno, S. Berweger, N. Prajapati, M. T. Simons, A. B. Artusio-Glimpse, C. L. Holloway, M. Jayaseelan, R. M. Potvliege, and C. S. Adams, Detection of 3–300 MHz electric fields using Floquet sideband gaps by “Rabi matching” dressed Rydberg atoms, J. Appl. Phys. 134, 134502 (2023).
  29. S. Kumar, H. Fan, H. Kübler, J. Sheng, and J. P. Shaffer, Atom-based sensing of weak radio frequency electric fields using homodyne readout, Sci. Rep. 7, 42981 (2017).
  30. M. T. Simons, A. H. Haddab, J. A. Gordon, and C. L. Holloway, A Rydberg atom-based mixer: Measuring the phase of a radio frequency wave, Appl. Phys. Lett. 114, 111105 (2019).
  31. D. H. Meyer, J. C. Hill, P. D. Kunz, and K. C. Cox, Simultaneous multiband demodulation using a Rydberg atomic sensor, Phys. Rev. Appl. 19, 014025 (2023).
  32. A. B. Deb and N. Kjaergaard, Radio-over-fiber using an optical antenna based on Rydberg states of atoms, Appl. Phys. Lett. 112, 211102 (2018).
  33. P. K. Elgee, J. C. Hill, K.-J. E. LeBlanc, G. D. Ko, P. D. Kunz, D. H. Meyer, and K. C. Cox, Satellite radio detection via dual-microwave Rydberg spectroscopy, Appl. Phys. Lett. 123, 084102 (2023).
  34. G. Allinson, M. J. Jamieson, A. R. Mackellar, L. Downes, C. S. Adams, and K. J. Weatherill, Simultaneous multiband radio-frequency detection using high-orbital-angular-momentum states in a Rydberg-atom receiver, Phys. Rev. Res. 6, 023317 (2024).
  35. R. C. Brown, B. Kayim, M. A. Viray, A. R. Perry, B. C. Sawyer, and R. Wyllie, Very-high- and ultrahigh-frequency electric-field detection using high angular momentum Rydberg states, Phys. Rev. A 107, 052605 (2023).
  36. A. Duspayev, R. Cardman, D. A. Anderson, and G. Raithel, High-angular-momentum Rydberg states in a room-temperature vapor cell for dc electric-field sensing, Phys. Rev. Res. 6, 023138 (2024).
  37. S. M. Bohaichuk, F. Ripka, V. Venu, F. Christaller, C. Liu, M. Schmidt, H. Kübler, and J. P. Shaffer, Three-photon Rydberg-atom-based radio-frequency sensing scheme with narrow linewidth, Phys. Rev. Appl. 20, L061004 (2023).
  38. K.-Y. Liao, H.-T. Tu, S.-Z. Yang, C.-J. Chen, X.-H. Liu, J. Liang, X.-D. Zhang, H. Yan, and S.-L. Zhu, Microwave electrometry via electromagnetically induced absorption in cold Rydberg atoms, Phys. Rev. A 101, 053432 (2020).
  39. F. Zhou, F. Jia, X. Liu, Y. Yu, J. Mei, J. Zhang, F. Xie, and Z. Zhong, Improving the spectral resolution and measurement range of quantum microwave electrometry by cold Rydberg atoms, J. Phys. B 56, 025001 (2023).
  40. D. J. McCarron, S. A. King, and S. L. Cornish, Modulation transfer spectroscopy in atomic rubidium, Meas. Sci. Technol. 19, 105601 (2008).
  41. B. E. Sherlock and I. G. Hughes, How weak is a weak probe in laser spectroscopy? Am. J. Phys. 77, 133 (2009).
  42. R. Duverger, A. Bonnin, R. Granier, Q. Marolleau, C. Blanchard, N. Zahzam, Y. Bidel, M. Cadoret, A. Bresson, and S. Schwartz, Metrology of microwave fields based on trap-loss spectroscopy with cold Rydberg atoms, Phys. Rev. Appl. 22, 044039 (2024).
  43. C. L. Holloway, M. T. Simons, A. H. Haddab, C. J. Williams, and M. W. Holloway, A “real-time” guitar recording using Rydberg atoms and electromagnetically induced transparency: Quantum physics meets music, AIP Adv. 9, 065213 (2019).
  44. M. Allegrini, E. Arimondo, and L. A. Orozco, Survey of hyperfine structure measurements in alkali atoms, J. Phys. Chem. Ref. Data 51, 043101 (2022).
  45. M. T. Simons, J. A. Gordon, C. L. Holloway, D. A. Anderson, S. A. Miller, and G. Raithel, Using frequency detuning to improve the sensitivity of electric field measurements via electromagnetically induced transparency and Autler-Townes splitting in Rydberg atoms, Appl. Phys. Lett. 108, 171101 (2016).
  46. I. Hughes and T. P. A. Hase, Measurements and Their Uncertainties: A Practical Guide to Modern Error Analysis (Oxford University Press, New York, 2010).
  47. C. L. Holloway, M. T. Simons, J. A. Gordon, A. Dienstfrey, D. A. Anderson, and G. Raithel, Electric field metrology for SI traceability: Systematic measurement uncertainties in electromagnetically induced transparency in atomic vapor, J. Appl. Phys. 121, 233101 (2017).
  48. S. Chen, D. J. Reed, A. R. MacKellar, L. A. Downes, N. F. A. Almuhawish, M. J. Jamieson, C. S. Adams, and K. J. Weatherill, Terahertz electrometry via infrared spectroscopy of atomic vapor, Optica 9, 485 (2022).
  49. H. Fan, S. Kumar, J. Sheng, J. P. Shaffer, C. L. Holloway, and J. A. Gordon, Effect of vapor-cell geometry on Rydberg-atom-based measurements of radio-frequency electric fields, Phys. Rev. Appl. 4, 044015 (2015).
  50. W. L. Barnes, S. A. R. Horsley, and W. L. Vos, Classical antennas, quantum emitters, and densities of optical states, J. Opt. 22, 073001 (2020).
  51. N. Prajapati, N. Bhusal, A. P. Rotunno, S. Berweger, M. T. Simons, A. B. Artusio-Glimpse, Y. Ju Wang, E. Bottomley, H. Fan, and C. L. Holloway, Sensitivity comparison of two-photon vs three-photon Rydberg electrometry, J. Appl. Phys. 134, 024504 (2023).
  52. I. I. Beterov, I. I. Ryabtsev, D. B. Tretyakov, and V. M. Entin, Quasiclassical calculations of blackbody-radiation-induced depopulation rates and effective lifetimes of Rydberg nS, nP, and nD alkali-metal atoms with n≤80, Phys. Rev. A 79, 052504 (2009).
  53. C. L. Holloway, J. A. Gordon, A. Schwarzkopf, D. A. Anderson, S. A. Miller, N. Thaicharoen, and G. Raithel, Sub-wavelength imaging and field mapping via electromagnetically induced transparency and Autler-Townes splitting in Rydberg atoms, Appl. Phys. Lett. 104, 241108 (2014).
  54. C. Foot, Atomic Physics (Oxford University Press, New York, 2005).
  55. J. Han, Y. Jamil, D. V. L. Norum, P. J. Tanner, and T. F. Gallagher, Rb nf quantum defects from millimeter-wave spectroscopy of cold 85Rb Rydberg atoms, Phys. Rev. A 74, 054502 (2006).
  56. A. Osterwalder and F. Merkt, Using high Rydberg states as electric field sensors, Phys. Rev. Lett. 82, 1831 (1999).
  57. J. D. Carter, O. Cherry, and J. D. D. Martin, Electric-field sensing near the surface microstructure of an atom chip using cold Rydberg atoms, Phys. Rev. A 86, 053401 (2012).
  58. B. Liu, L. H. Zhang, Z. K. Liu, Z. A. Deng, D. S. Ding, B. S. Shi, and G. C. Guo, Electric field measurement and application based on Rydberg atoms, arXiv:2305.16696.
  59. K. J. Weatherill, J. D. Pritchard, R. P. Abel, M. G. Bason, A. K. Mohapatra, and C. S. Adams, Electromagnetically induced transparency of an interacting cold Rydberg ensemble, J. Phys. B 41, 201002 (2008).
  60. G. Allinson, L. A. Downes, C. S. Adams, and K. J. Weatherill, Determination of quantum defects and core polarizability of atomic cesium via terahertz and radio-frequency spectroscopy in thermal vapor, Phys. Rev. A 111, 062802 (2025).
  61. https://doi.org/doi:10.15128/r28w32r568j

Outline

Information

Phys. Rev. Applied 24, 034022– Published 8 September, 2025
  • Received 4 April 2025
  • Revised 9 July 2025
  • Accepted 11 August 2025
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