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  • Featured in Physics
  • Open Access

Engineered Molecular Clock Transitions for Precision Measurements

Yuiki Takahashi*, Harish D. Ramachandran†, Arian Jadbabaie‡, Yi Zeng§, Chi Zhang, and Nicholas R. Hutzler

  • *Contact author: yuiki@caltech.edu
  • †Present address: Department of Physics, The Johns Hopkins University, Baltimore, Maryland 21218, USA.
  • ‡Present address: Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
  • §Present address: Institut für Experimentalphysik, Universität Innsbruck, A-6020 Innsbruck, Austria.
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Phys. Rev. X 16, 031011 – Published 20 July, 2026

DOI: https://doi.org/10.1103/4t7q-d58r

Abstract

Heavy polar molecules are sensitive probes of physics beyond the standard model. However, uncontrolled external electromagnetic fields pose challenges to achieving precise and accurate measurements. Minimizing susceptibility to these fields is therefore critical and has played an important role in all precision experiments of this type. Here we devise and demonstrate clock transitions engineered to realize robust symmetry violation searches in the polyatomic molecule YbOH. Sensitivities to external fields can be suppressed by orders of magnitude while preserving high sensitivity to the electron electric dipole moment. We perform Ramsey measurements on these clock transitions and observe suppression of electric and magnetic sensitivities by at least factors of 700 and 200, respectively, and demonstrate the robustness of their spin coherence against large electromagnetic-field fluctuations. We further identify and employ selected quantum states to make sensitive measurements of external magnetic and electric fields, another critical feature for highly accurate measurements. This approach of molecular engineering is broadly applicable to diverse molecular species and states, including those with complex nuclei and those that are compatible with state-of-the-art cooling and trapping techniques, thereby offering the potential to significantly improve experimental sensitivity to a wide range of new physics while expanding the chemical design space for molecular quantum science.

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Noise Proofing Molecules for New-Physics Searches

Published 20 July, 2026

Certain molecules can be placed into states that are less sensitive to external noise, offering researchers a quiet system for probing fundamental physics.

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Popular Summary

Heavy polar molecules are sensitive probes of physics beyond the standard model, but uncontrolled external electric and magnetic noise poses challenges to achieving precise and accurate measurements. We overcome this by engineering molecular clock transitions in the polyatomic molecule YbOH at special external field configurations to cancel out these noise sources. Our approach suppresses sensitivities to external fields by orders of magnitude while preserving high sensitivity to the electron electric dipole moment. We further engineer transitions to perform precise measurements of the electromagnetic environment in situ to diagnose unwanted systematic shifts. We anticipate this molecular engineering approach will be broadly applicable to diverse molecular species, offering the potential to improve experimental sensitivity to new physics while expanding the chemical design space for molecular quantum science.

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References (70)

  1. S. L. Cornish, M. R. Tarbutt, and K. R. A. Hazzard, Quantum computation and quantum simulation with ultracold molecules, Nat. Phys. 20, 730 (2024).
  2. T. Karman, M. Tomza, and J. Pérez-Ríos, Ultracold chemistry as a testbed for few-body physics, Nat. Phys. 20, 722 (2024).
  3. D. DeMille, N. R. Hutzler, A. M. Rey, and T. Zelevinsky, Quantum sensing and metrology for fundamental physics with molecules, Nat. Phys. 20, 741 (2024).
  4. O. P. Sushkov and V. V. Flambaum, Parity breaking effects in diatomic molecules, Sov. Phys. JETP 48, 608 (1978).
  5. M. S. Safronova, D. Budker, D. DeMille, Derek F. Jackson Kimball, A. Derevianko, and C. W. Clark, Search for new physics with atoms and molecules, Rev. Mod. Phys. 90, 025008 (2018).
  6. N. R. Hutzler, Polyatomic molecules as quantum sensors for fundamental physics, Quantum Sci. Technol. 5, 044011 (2020).
  7. T. S. Roussy, L. Caldwell, T. Wright, W. B. Cairncross, Y. Shagam, K. B. Ng, N. Schlossberger, S. Y. Park, A. Wang, J. Ye, and E. A. Cornell, An improved bound on the electron’s electric dipole moment, Science 381, 46 (2023).
  8. V. Andreev, D. G. Ang, D. DeMille, J. M. Doyle, G. Gabrielse, J. Haefner, N. R. Hutzler, Z. Lasner, C. Meisenhelder, B. R. O’Leary, C. D. Panda, A. D. West, E. P. West, and X. Wu, Improved limit on the electric dipole moment of the electron, Nature (London) 562, 355 (2018).
  9. R. Stutz and E. Cornell, Search for the electron EDM using trapped molecular ions, Bull. Am. Phys. Soc. 89, 76 (2004).
  10. D. DeMille, F. Bay, S. Bickman, D. Kawall, D. Krause, S. E. Maxwell, and L. R. Hunter, Investigation of PbO as a system for measuring the electric dipole moment of the electron, Phys. Rev. A 61, 052507 (2000).
  11. R. Alarcon et al., Electric dipole moments and the search for new physics, arXiv:2203.08103.
  12. T. A. Isaev and R. Berger, Polyatomic candidates for cooling of molecules with lasers from simple theoretical concepts, Phys. Rev. Lett. 116, 063006 (2016).
  13. I. Kozyryev, L. Baum, K. Matsuda, and J. M. Doyle, Proposal for laser cooling of complex polyatomic molecules, ChemPhysChem 17, 3641 (2016).
  14. N. Fitch and M. Tarbutt, Laser-cooled molecules, Adv. At. Mol. Opt. Phys. 70, 157 (2021).
  15. F. J. Collings, N. J. Fitch, R. A. Jenkins, J. M. Dyne, E. Wursten, M. T. Ziemba, X. S. Zheng, F. Castellini, J. Lim, B. E. Sauer, and M. R. Tarbutt, Low-noise environment for probing fundamental symmetries, New J. Phys. 27, 105004 (2025).
  16. O. Grasdijk, O. Timgren, J. Kastelic, T. Wright, S. Lamoreaux, D. DeMille, K. Wenz, M. Aitken, T. Zelevinsky, T. Winick, and D. Kawall, CeNTREX: A new search for time-reversal symmetry violation in the 205 Tl nucleus, Quantum Sci. Technol. 6, 044007 (2021).
  17. Y. Takahashi, C. Zhang, A. Jadbabaie, and N. R. Hutzler, Engineering field-insensitive molecular clock transitions for symmetry violation searches, Phys. Rev. Lett. 131, 183003 (2023).
  18. M. Verma, A. M. Jayich, and A. C. Vutha, Electron electric dipole moment searches using clock transitions in ultracold molecules, Phys. Rev. Lett. 125, 153201 (2020).
  19. C. Ho, J. Lim, B. Sauer, and M. Tarbutt, Measuring the nuclear magnetic quadrupole moment in heavy polar molecules, Front. Phys. 11, 1086980 (2023).
  20. L. Anderegg, N. B. Vilas, C. Hallas, P. Robichaud, A. Jadbabaie, J. M. Doyle, and N. R. Hutzler, Quantum control of trapped polyatomic molecules for eEDM searches, Science 382, 665 (2023).
  21. A. Derevianko and H. Katori, Colloquium: Physics of optical lattice clocks, Rev. Mod. Phys. 83, 331 (2011).
  22. A. D. Ludlow, M. M. Boyd, J. Ye, E. Peik, and P. O. Schmidt, Optical atomic clocks, Rev. Mod. Phys. 87, 637 (2015).
  23. H. Kim, H. S. Han, and D. Cho, Magic polarization for optical trapping of atoms without stark-induced dephasing, Phys. Rev. Lett. 111, 243004 (2013).
  24. I. Ushijima, M. Takamoto, and H. Katori, Operational magic intensity for sr optical lattice clocks, Phys. Rev. Lett. 121, 263202 (2018).
  25. S. Kotochigova and D. DeMille, Electric-field-dependent dynamic polarizability and state-insensitive conditions for optical trapping of diatomic polar molecules, Phys. Rev. A 82, 063421 (2010).
  26. S. Burchesky, L. Anderegg, Y. Bao, S. S. Yu, E. Chae, W. Ketterle, K.-K. Ni, and J. M. Doyle, Rotational coherence times of polar molecules in optical tweezers, Phys. Rev. Lett. 127, 123202 (2021).
  27. K. H. Leung, B. Iritani, E. Tiberi, I. Majewska, M. Borkowski, R. Moszynski, and T. Zelevinsky, Terahertz vibrational molecular clock with systematic uncertainty at the 10−14 level, Phys. Rev. X 13, 011047 (2023).
  28. 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).
  29. M. Denis, Pi A. B. Haase, Rob G. E. Timmermans, E. Eliav, N. R. Hutzler, and A. Borschevsky, Enhancement factor for the electric dipole moment of the electron in the BaOH and YbOH molecules, Phys. Rev. A 99, 042512 (2019).
  30. J. Baron, W. C. Campbell, D. DeMille, J. M. Doyle, G. Gabrielse, Y. V. Gurevich, P. W. Hess, N. R. Hutzler, E. Kirilov, I. Kozyryev, B. R. O’Leary, C. D. Panda, M. F. Parsons, B. Spaun, A. C. Vutha, A. D. West, and E. P. West, Methods, analysis, and the treatment of systematic errors for the electron electric dipole moment search in thorium monoxide, New J. Phys. 19, 073029 (2017).
  31. I. Kozyryev and N. R. Hutzler, Precision measurement of time-reversal symmetry violation with laser-cooled polyatomic molecules, Phys. Rev. Lett. 119, 133002 (2017).
  32. T. S. Roussy, D. A. Palken, W. B. Cairncross, B. M. Brubaker, D. N. Gresh, M. Grau, K. C. Cossel, K. B. Ng, Y. Shagam, Y. Zhou, V. V. Flambaum, K. W. Lehnert, J. Ye, and E. A. Cornell, Experimental constraint on axionlike particles over seven orders of magnitude in mass, Phys. Rev. Lett. 126, 171301 (2021).
  33. M. Fan, B. Nima, A. Radak, G. Alonso-Álvarez, and A. Vutha, Wideband search for axionlike dark matter using octupolar nuclei in a crystal, Phys. Rev. Lett. 136, 121802 (2026).
  34. K. Gaul and R. Berger, Ab initio study of parity and time-reversal violation in laser-coolable triatomic molecules, Phys. Rev. A 101, 012508 (2020).
  35. V. V. Flambaum, D. DeMille, and M. G. Kozlov, Time-reversal symmetry violation in molecules induced by nuclear magnetic quadrupole moments, Phys. Rev. Lett. 113, 103003 (2014).
  36. E. Kirilov, W. C. Campbell, J. M. Doyle, G. Gabrielse, Y. V. Gurevich, P. W. Hess, N. R. Hutzler, B. R. O’Leary, E. Petrik, B. Spaun, A. C. Vutha, and D. DeMille, Shot-noise-limited spin measurements in a pulsed molecular beam, Phys. Rev. A 88, 013844 (2013).
  37. A. Petrov and A. Zakharova, Sensitivity of the YbOH molecule to P,T-odd effects in an external electric field, Phys. Rev. A 105, L050801 (2022).
  38. A. Jadbabaie, Y. Takahashi, N. H. Pilgram, C. J. Conn, Y. Zeng, C. Zhang, and N. R. Hutzler, Characterizing the fundamental bending vibration of a linear polyatomic molecule for symmetry violation searches, New J. Phys. 25, 073014 (2023).
  39. H. Loh, K. C. Cossel, M. C. Grau, K.-K. Ni, E. R. Meyer, J. L. Bohn, J. Ye, and E. A. Cornell, Precision spectroscopy of polarized molecules in an ion trap, Science 342, 1220 (2013).
  40. L. Caldwell, T. S. Roussy, T. Wright, W. B. Cairncross, Y. Shagam, K. B. Ng, N. Schlossberger, S. Y. Park, A. Wang, J. Ye, and E. A. Cornell, Systematic and statistical uncertainty evaluation of the hff+ electron electric dipole moment experiment, Phys. Rev. A 108, 012804 (2023).
  41. X. Wu, Z. Han, J. Chow, D. G. Ang, C. Meisenhelder, C. D. Panda, E. P. West, G. Gabrielse, J. M. Doyle, and D. DeMille, The metastable Q3Δ2 state of ThO: A new resource for the ACME electron EDM search, New J. Phys. 22, 023013 (2020).
  42. N. H. Pilgram, A. Jadbabaie, Y. Zeng, N. R. Hutzler, and T. C. Steimle, Fine and hyperfine interactions in Yb171OH and Yb173OH, J. Chem. Phys. 154, 244309 (2021).
  43. T. Chen, C. Zhang, L. Cheng, K. B. Ng, S. Malbrunot-Ettenauer, V. V. Flambaum, Z. Lasner, J. M. Doyle, P. Yu, C. J. Conn, C. Zhang, N. R. Hutzler, A. M. Jayich, B. Augenbraun, and D. DeMille, Relativistic exact two-component coupled-cluster study of molecular sensitivity factors for nuclear schiff moments, J. Phys. Chem. A 128, 6540 (2024). pMID: 39047199.
  44. K. C. Stuntz, K. L. Rice, L. Cheng, and B. L. Augenbraun, Optical cycling and sensitivity to the electron’s electric dipole moment in gold-containing molecules, Phys. Rev. A 110, 042807 (2024).
  45. A. Sunaga, Y. Takahashi, A. Vutha, and Y. Takahashi, Measuring the nuclear magnetic quadrupole moment of optically trapped ytterbium atoms in the metastable state, New J. Phys. 26, 023023 (2024).
  46. B. L. Augenbraun, Z. D. Lasner, A. Frenett, H. Sawaoka, C. Miller, T. C. Steimle, and J. M. Doyle, Laser-cooled polyatomic molecules for improved electron electric dipole moment searches, New J. Phys. 22, 022003 (2020).
  47. X. Alauze, J. Lim, M. A. Trigatzis, S. Swarbrick, F. J. Collings, N. J. Fitch, B. E. Sauer, and M. R. Tarbutt, An ultracold molecular beam for testing fundamental physics, Quantum Sci. Technol. 6, 044005 (2021).
  48. N. J. Fitch, J. Lim, E. A. Hinds, B. E. Sauer, and M. R. Tarbutt, Methods for measuring the electron’s electric dipole moment using ultracold ybf molecules, Quantum Sci. Technol. 6, 014006 (2020).
  49. R. A. Jenkins, M. T. Ziemba, F. J. Collings, X. S. Zheng, F. Castellini, E. Wursten, J. Lim, B. E. Sauer, and M. R. Tarbutt, Spin interferometry in a beam of ultracold molecules, arXiv:2602.00713.
  50. E. Fraval, M. J. Sellars, and J. J. Longdell, Method of extending hyperfine coherence times in Pr3+: Y2SiO5, Phys. Rev. Lett. 92, 077601 (2004).
  51. M. Fan, B. Nima, A. Radak, G. Alonso-Álvarez, and A. Vutha, First results from a search for axionlike dark matter using octupole-deformed nuclei in a crystal, arXiv:2410.02218.
  52. A. Marc, M. Hubert, and T. Fleig, Candidate molecules for next-generation searches of hadronic charge-parity violation, Phys. Rev. A 108, 062815 (2023).
  53. M. Śmiałkowski and M. Tomza, Highly polar molecules consisting of a copper or silver atom interacting with an alkali-metal or alkaline-earth-metal atom, Phys. Rev. A 103, 022802 (2021).
  54. M. Löw, M. Ibrügger, G. Rempe, and M. Zeppenfeld, Coherence of symmetry-protected rotational qubits in cold polyatomic molecules, Phys. Rev. Lett. 134, 113402 (2025).
  55. C. Zhang, P. Yu, A. Jadbabaie, and N. R. Hutzler, Quantum-enhanced metrology for molecular symmetry violation using decoherence-free subspaces, Phys. Rev. Lett. 131, 193602 (2023).
  56. K. Najafian, Z. Meir, and S. Willitsch, From megahertz to terahertz qubits encoded in molecular ions: Theoretical analysis of dipole-forbidden spectroscopic transitions in N2+, Phys. Chem. Chem. Phys. 22, 23083 (2020).
  57. A. Prehn, M. Ibrügger, G. Rempe, and M. Zeppenfeld, High-resolution “magic”-field spectroscopy on trapped polyatomic molecules, Phys. Rev. Lett. 127, 173602 (2021).
  58. Y. Takahashi, H. D. Ramachandran, A. Jadbabaie, Y. Zeng, C. Zhang, and N. R. Hutzler, Data supporting the figures and analysis in “Engineered Molecular Clock Transitions for Precision Measurements,” https://github.com/YuikiTakahashi/Yuiki_Takahashi_magic_demonstration_data_PRX_2026 (2026) (accessed: 2026-05-03).
  59. A. Jadbabaie, N. H. Pilgram, J. Klos, S. Kotochigova, and N. R. Hutzler, Enhanced molecular yield from a cryogenic buffer gas beam source via excited state chemistry, New J. Phys. 22, 022002 (2020).
  60. N. R. Hutzler, H.-I. Lu, and J. M. Doyle, The buffer gas beam: An intense, cold, and slow source for atoms and molecules., Chem. Rev. 112, 4803 (2012).
  61. Y. Takahashi, D. Shlivko, G. Woolls, and N. R. Hutzler, Simulation of cryogenic buffer gas beams, Phys. Rev. Res. 3, 023018 (2021).
  62. A. Jadbabaie, Measuring fundamental symmetry violation in polyatomic molecules, Ph. D. thesis, California Institute of Technology, 2023.
  63. R. Santra, E. Arimondo, T. Ido, C. H. Greene, and J. Ye, High-accuracy optical clock via three-level coherence in neutral bosonic Sr88, Phys. Rev. Lett. 94, 173002 (2005).
  64. T. Zanon-Willette, A. D. Ludlow, S. Blatt, M. M. Boyd, E. Arimondo, and J. Ye, Cancellation of stark shifts in optical lattice clocks by use of pulsed raman and electromagnetically induced transparency techniques, Phys. Rev. Lett. 97, 233001 (2006).
  65. A. V. Taichenachev, V. I. Yudin, C. W. Oates, Z. W. Barber, N. D. Lemke, A. D. Ludlow, U. Sterr, C. Lisdat, and F. Riehle, Compensation of field-induced frequency shifts in ramsey spectroscopy of optical clock transitions, JETP Lett. 90, 713 (2010).
  66. V. I. Yudin, A. V. Taichenachev, C. W. Oates, Z. W. Barber, N. D. Lemke, A. D. Ludlow, U. Sterr, C. Lisdat, and F. Riehle, Hyper-Ramsey spectroscopy of optical clock transitions, Phys. Rev. A 82, 011804(R) (2010).
  67. R. Hobson, W. Bowden, S. A. King, P. E. G. Baird, I. R. Hill, and P. Gill, Modified hyper-ramsey methods for the elimination of probe shifts in optical clocks, Phys. Rev. A 93, 010501(R) (2016).
  68. Z.-X. Duan, W.-T. Wu, Y.-T. Lin, and S.-J. Yang, Simple and active magnetic-field stabilization for cold atom experiments, Rev. Sci. Instrum. 93, 123201 (2022).
  69. J. Baron, W. C. Campbell, D. DeMille, J. M. Doyle, G. Gabrielse, Y. V. Gurevich, P. W. Hess, N. R. Hutzler, E. Kirilov, I. Kozyryev, B. R. O’Leary, C. D. Panda, M. F. Parsons, E. S. Petrik, B. Spaun, A. C. Vutha, and A. D. West, Order of magnitude smaller limit on the electric dipole moment of the electron, Science 343, 269 (2014).
  70. N. R. Hutzler, A new limit on the electron electric dipole moment, Ph.D. thesis, Harvard University, 2014.

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Phys. Rev. X 16, 031011– Published 20 July, 2026
  • Received 8 October 2025
  • Accepted 28 April 2026
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