- Physical Review Journals
All JournalsPhysics Magazine

Physical Review Letters

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

Universal Global Gates for a Fine-Structure Qubit in Strontium-88

Renhao Tao1,2,3, Ohad Lib1,2, Flavien Gyger1,2, Hendrik Timme1,2, Maximilian Ammenwerth1,2, Immanuel Bloch1,2,3, and Johannes Zeiher1,2,3,*

  • *Contact author: johannes.zeiher@mpq.mpg.de
PDF

Phys. Rev. Lett. 136, 153602 – Published 16 April, 2026

DOI: https://doi.org/10.1103/gj3b-5ngl

Abstract

Metastable atomic qubits are a highly promising platform for the realization of quantum computers, owing to their scalability and the possibility of converting leakage errors to erasure errors midcircuit. Here, we demonstrate and characterize a high-fidelity quantum gate set for the metastable fine-structure qubit encoded between the P03 and P23 states in bosonic strontium-88. We find single-qubit gate fidelities of 0.993(1), and two-qubit gate fidelities of 0.9945(6) after correcting for losses during the gate operation. Furthermore, we present a novel state-resolved detection scheme for the two fine-structure states that enables high-fidelity detection of qubit loss. Finally, we leverage the existence of a stable ground state outside the qubit subspace to perform midcircuit erasure conversion using fast destructive imaging. Our results establish the strontium fine-structure qubit as a promising candidate for near-term error-corrected quantum computers, offering unique scaling perspectives.

View figure in article

Physics Subject Headings (PhySH)

Article Text

Supplemental Material

References (76)

  1. M. Saffman, T. G. Walker, and K. Mølmer, Quantum information with Rydberg atoms, Rev. Mod. Phys. 82, 2313 (2010).
  2. M. Saffman, Quantum computing with atomic qubits and Rydberg interactions: Progress and challenges, J. Phys. B 49, 202001 (2016).
  3. L. Henriet, L. Beguin, A. Signoles, T. Lahaye, A. Browaeys, G.-O. Reymond, and C. Jurczak, Quantum computing with neutral atoms, Quantum 4, 327 (2020).
  4. M. Morgado and S. Whitlock, Quantum simulation and computing with Rydberg-interacting qubits, AVS Quantum Sci. 3, 023501 (2021).
  5. C. Sheng, X. He, P. Xu, R. Guo, K. Wang, Z. Xiong, M. Liu, J. Wang, and M. Zhan, High-fidelity single-qubit gates on neutral atoms in a two-dimensional magic-intensity optical dipole trap array, Phys. Rev. Lett. 121, 240501 (2018).
  6. T. M. Graham, Y. Song, J. Scott et al., Multi-qubit entanglement and algorithms on a neutral-atom quantum computer, Nature (London) 604, 457 (2022).
  7. S. Ma, G. Liu, P. Peng, B. Zhang, S. Jandura, J. Claes, A. P. Burgers, G. Pupillo, S. Puri, and J. D. Thompson, High-fidelity gates and mid-circuit erasure conversion in an atomic qubit, Nature (London) 622, 279 (2023).
  8. B. Nikolov, E. Diamond-Hitchcock, J. Bass, N. L. R. Spong, and J. D. Pritchard, Randomized benchmarking using nondestructive readout in a two-dimensional atom array, Phys. Rev. Lett. 131, 030602 (2023).
  9. J. A. Muniz, M. Stone, D. T. Stack et al., High-fidelity universal gates in the Yb171 ground-state nuclear-spin qubit, PRX Quantum 6, 020334 (2025).
  10. L. Yan, S. Lannig, W. R. Milner, M. N. Frankel, B. Lewis, D. Lee, K. Kim, and J. Ye, High-power clock laser spectrally tailored for high-fidelity quantum state engineering, Phys. Rev. X 15, 031055 (2025).
  11. S. J. Evered, D. Bluvstein, M. Kalinowski, S. Ebadi, T. Manovitz, H. Zhou, S. H. Li, A. A. Geim, T. T. Wang, N. Maskara, H. Levine, G. Semeghini, M. Greiner, V. Vuletić, and M. D. Lukin, High-fidelity parallel entangling gates on a neutral-atom quantum computer, Nature (London) 622, 268 (2023).
  12. R. Finkelstein, R. B.-S. Tsai, X. Sun, P. Scholl, S. Direkci, T. Gefen, J. Choi, A. L. Shaw, and M. Endres, Universal quantum operations and ancilla-based read-out for tweezer clocks, Nature (London) 634, 321 (2024).
  13. A. G. Radnaev, W. C. Chung, D. C. Cole et al., Universal neutral-atom quantum computer with individual optical addressing and nondestructive readout, PRX Quantum 6, 030334 (2025).
  14. R. B.-S. Tsai, X. Sun, A. L. Shaw, R. Finkelstein, and M. Endres, Benchmarking and fidelity response theory of high-fidelity Rydberg entangling gates, PRX Quantum 6, 010331 (2025).
  15. L. Pause, L. Sturm, M. Mittenbühler, S. Amann, T. Preuschoff, D. Schäffner, M. Schlosser, and G. Birkl, Supercharged two-dimensional tweezer array with more than 1000 atomic qubits, Optica 11, 222 (2024).
  16. G. Pichard, D. Lim, É. Bloch, J. Vaneecloo, L. Bourachot, G.-J. Both, G. Mériaux, S. Dutartre, R. Hostein, J. Paris, B. Ximenez, A. Signoles, A. Browaeys, T. Lahaye, and D. Dreon, Rearrangement of individual atoms in a 2000-site optical-tweezer array at cryogenic temperatures, Phys. Rev. Appl. 22, 024073 (2024).
  17. R. Tao, M. Ammenwerth, F. Gyger, I. Bloch, and J. Zeiher, High-fidelity detection of large-scale atom arrays in an optical lattice, Phys. Rev. Lett. 133, 013401 (2024).
  18. F. Gyger, M. Ammenwerth, R. Tao, H. Timme, S. Snigirev, I. Bloch, and J. Zeiher, Continuous operation of large-scale atom arrays in optical lattices, Phys. Rev. Res. 6, 033104 (2024).
  19. M. A. Norcia, H. Kim, W. B. Cairncross et al., Iterative assembly of Yb171 atom arrays with cavity-enhanced optical lattices, PRX Quantum 5, 030316 (2024).
  20. R. Lin, H.-S. Zhong, Y. Li, Z.-R. Zhao, L.-T. Zheng, T.-R. Hu, H.-M. Wu, Z. Wu, W.-J. Ma, Y. Gao, Y.-K. Zhu, Z.-F. Su, W.-L. Ouyang, Y.-C. Zhang, J. Rui, M.-C. Chen, C.-Y. Lu, and J.-W. Pan, Ai-enabled parallel assembly of thousands of defect-free neutral atom arrays, Phys. Rev. Lett. 135, 060602 (2025).
  21. H. J. Manetsch, G. Nomura, E. Bataille, X. Lv, K. H. Leung, and M. Endres, A tweezer array with 6,100 highly coherent atomic qubits, Nature (London) 647, 60 (2025).
  22. D. Bluvstein, H. Levine, G. Semeghini, T. T. Wang, S. Ebadi, M. Kalinowski, A. Keesling, N. Maskara, H. Pichler, M. Greiner, V. Vuletić, and M. D. Lukin, A quantum processor based on coherent transport of entangled atom arrays, Nature (London) 604, 451 (2022).
  23. D. Bluvstein et al., Logical quantum processor based on reconfigurable atom arrays, Nature (London) 626, 58 (2024).
  24. B. W. Reichardt, A. Paetznick, D. Aasen et al., Logical computation demonstrated with a neutral atom quantum processor, arXiv:2411.11822.
  25. M. J. Bedalov, M. Blakely, P. D. Buttler et al., Fault-tolerant operation and materials science with neutral atom logical qubits, arXiv:2412.07670.
  26. D. K. Tuckett, S. D. Bartlett, and S. T. Flammia, Ultrahigh error threshold for surface codes with biased noise, Phys. Rev. Lett. 120, 050505 (2018).
  27. D. K. Tuckett, S. D. Bartlett, S. T. Flammia, and B. J. Brown, Fault-tolerant thresholds for the surface code in excess of 5% under biased noise, Phys. Rev. Lett. 124, 130501 (2020).
  28. R. Lescanne, M. Villiers, T. Peronnin, A. Sarlette, M. Delbecq, B. Huard, T. Kontos, M. Mirrahimi, and Z. Leghtas, Exponential suppression of bit-flips in a qubit encoded in an oscillator, Nat. Phys. 16, 509 (2020).
  29. I. Cong, H. Levine, A. Keesling, D. Bluvstein, S.-T. Wang, and M. D. Lukin, Hardware-efficient, fault-tolerant quantum computation with Rydberg atoms, Phys. Rev. X 12, 021049 (2022).
  30. Q. Xu, N. Mannucci, A. Seif, A. Kubica, S. T. Flammia, and L. Jiang, Tailored XZZX codes for biased noise, Phys. Rev. Res. 5, 013035 (2023).
  31. K. Sahay, J. Jin, J. Claes, J. D. Thompson, and S. Puri, High-threshold codes for neutral-atom qubits with biased erasure errors, Phys. Rev. X 13, 041013 (2023).
  32. P. Scholl, A. L. Shaw, R. B.-S. Tsai, R. Finkelstein, J. Choi, and M. Endres, Erasure conversion in a high-fidelity Rydberg quantum simulator, Nature (London) 622, 273 (2023).
  33. A. Kubica, A. Haim, Y. Vaknin, H. Levine, F. Brandão, and A. Retzker, Erasure qubits: Overcoming the T1 limit in superconducting circuits, Phys. Rev. X 13, 041022 (2023).
  34. A. Alase, K. D. Stubbs, B. C. Sanders, and D. L. Feder, Erasure conversion in Majorana qubits via local quasiparticle detection, Phys. Rev. Res. 6, 043294 (2024).
  35. K. S. Chou, T. Shemma, H. McCarrick et al., A superconducting dual-rail cavity qubit with erasure-detected logical measurements, Nat. Phys. 20, 1454 (2024).
  36. C. M. Holland, Y. Lu, S. J. Li, C. L. Welsh, and L. W. Cheuk, Demonstration of erasure conversion in a molecular tweezer array, arXiv:2406.02391.
  37. H. Levine, A. Haim, J. S. C. Hung et al., Demonstrating a long-coherence dual-rail erasure qubit using tunable transmons, Phys. Rev. X 14, 011051 (2024).
  38. A. Quinn, G. J. Gregory, I. D. Moore, S. Brudney, J. Metzner, E. R. Ritchie, J. O’Reilly, D. J. Wineland, and D. T. C. Allcock, High-fidelity entanglement of metastable trapped-ion qubits with integrated erasure conversion, arXiv:2411.12727.
  39. J. T. Wilson, S. Saskin, Y. Meng, S. Ma, R. Dilip, A. P. Burgers, and J. D. Thompson, Trapping alkaline earth Rydberg atoms optical tweezer arrays, Phys. Rev. Lett. 128, 033201 (2022).
  40. J. W. Lis, A. Senoo, W. F. McGrew, F. Rönchen, A. Jenkins, and A. M. Kaufman, Midcircuit Operations using the omg architecture in neutral atom arrays, Phys. Rev. X 13, 041035 (2023).
  41. M. Kang, W. C. Campbell, and K. R. Brown, Quantum error correction with metastable states of trapped ions using erasure conversion, PRX Quantum 4, 020358 (2023).
  42. K. Barnes, P. Battaglino, B. J. Bloom et al., Assembly and coherent control of a register of nuclear spin qubits, Nat. Commun. 13, 2779 (2022).
  43. J. P. Covey, I. S. Madjarov, A. Cooper, and M. Endres, 2000-Times repeated imaging of strontium atoms in clock-magic tweezer arrays, Phys. Rev. Lett. 122, 173201 (2019).
  44. G. Unnikrishnan, P. Ilzhöfer, A. Scholz, C. Hölzl, A. Götzelmann, R. K. Gupta, J. Zhao, J. Krauter, S. Weber, N. Makki, H. P. Büchler, T. Pfau, and F. Meinert, Coherent control of the fine-structure qubit in a single alkaline-earth atom, Phys. Rev. Lett. 132, 150606 (2024).
  45. S. Pucher, V. Klüsener, F. Spriestersbach, J. Geiger, A. Schindewolf, I. Bloch, and S. Blatt, Fine-structure qubit encoded in metastable strontium trapped in an optical lattice, Phys. Rev. Lett. 132, 150605 (2024).
  46. M. Ammenwerth, H. Timme, F. Gyger, R. Tao, I. Bloch, and J. Zeiher, Realization of a fast triple-magic all-optical qutrit in Sr88, Phys. Rev. Lett. 135, 143401 (2025).
  47. See Supplement Material at http://link.aps.org/supplemental/10.1103/gj3b-5ngl, which includes Refs. [48–51].
  48. M. A. Norcia, A. W. Young, and A. M. Kaufman, Microscopic control and detection of ultracold strontium in optical-tweezer arrays, Phys. Rev. X 8, 041054 (2018).
  49. M. A. Norcia, A. W. Young, W. J. Eckner, E. Oelker, J. Ye, and A. M. Kaufman, Seconds-scale coherence on an optical clock transition in a tweezer array, Science 366, 93 (2019).
  50. T. Denecker, Y. T. Chew, O. Guillemant, G. Watanabe, T. Tomita, K. Ohmori, and S. de Léséleuc, Measurement and feedforward correction of the fast phase noise of lasers, Phys. Rev. A 111, 042614 (2025).
  51. A. Cao, W. J. Eckner, T. Lukin Yelin, A. W. Young, S. Jandura, L. Yan, K. Kim, G. Pupillo, J. Ye, N. Darkwah Oppong, and A. M. Kaufman, Multi-qubit gates and schrödinger cat states in an optical clock, Nature (London) 634, 315 (2024).
  52. I. S. Madjarov, J. P. Covey, A. L. Shaw, J. Choi, A. Kale, A. Cooper, H. Pichler, V. Schkolnik, J. R. Williams, and M. Endres, High-fidelity entanglement and detection of alkaline-earth Rydberg atoms, Nat. Phys. 16, 857 (2020).
  53. S. Ma, J. Dolde, X. Zheng, D. Ganapathy, A. Shtov, J. Chen, A. Stöltzel, B. J. Christensen, and S. Kolkowitz, Enhancing optical lattice clock coherence times with erasure conversion, PRX Quantum 6, 040340 (2025).
  54. A. Bergschneider, V. M. Klinkhamer, J. H. Becher, R. Klemt, G. Zürn, P. M. Preiss, and S. Jochim, Spin-resolved single-atom imaging of Li6 in free space, Phys. Rev. A 97, 063613 (2018).
  55. L. Su, A. Douglas, M. Szurek, A. H. Hébert, A. Krahn, R. Groth, G. A. Phelps, O. Marković, and M. Greiner, Fast single atom imaging for optical lattice arrays, Nat. Commun. 16, 1017 (2025).
  56. S. Stellmer and F. Schreck, Reservoir spectroscopy of 5s5p p23–5snd D31,2,3 transitions in strontium, Phys. Rev. A 90, 022512 (2014).
  57. E. Nielsen, K. Rudinger, T. Proctor, A. Russo, K. Young, and R. Blume-Kohout, pygsti: A python package for quantum gate set tomography, randomized benchmarking, and other QCVV protocols (2020).
  58. E. Nielsen, K. Rudinger, T. Proctor, A. Russo, K. Young, and R. Blume-Kohout, Probing quantum processor performance with pygsti, Quantum Sci. Technol. 5, 044002 (2020).
  59. S. Jandura and G. Pupillo, Time-optimal two- and three-qubit gates for Rydberg atoms, Quantum 6, 712 (2022).
  60. A. Fuhrmanek, R. Bourgain, Y. R. P. Sortais, and A. Browaeys, Free-space lossless state detection of a single trapped atom, Phys. Rev. Lett. 106, 133003 (2011).
  61. M. J. Gibbons, C. D. Hamley, C.-Y. Shih, and M. S. Chapman, Nondestructive fluorescent state detection of single neutral atom qubits, Phys. Rev. Lett. 106, 133002 (2011).
  62. M. Martinez-Dorantes, W. Alt, J. Gallego, S. Ghosh, L. Ratschbacher, Y. Völzke, and D. Meschede, Fast nondestructive parallel readout of neutral atom registers in optical potentials, Phys. Rev. Lett. 119, 180503 (2017).
  63. M. Kwon, M. F. Ebert, T. G. Walker, and M. Saffman, Parallel low-loss measurement of multiple atomic qubits, Phys. Rev. Lett. 119, 180504 (2017).
  64. M. Boll, T. A. Hilker, G. Salomon, A. Omran, J. Nespolo, L. Pollet, I. Bloch, and C. Gross, Spin- and density-resolved microscopy of antiferromagnetic correlations in Fermi-Hubbard chains, Science 353, 1257 (2016).
  65. J. Koepsell, S. Hirthe, D. Bourgund, P. Sompet, J. Vijayan, G. Salomon, C. Gross, and I. Bloch, Robust bilayer charge pumping for spin- and density-resolved quantum gas microscopy, Phys. Rev. Lett. 125, 010403 (2020).
  66. T.-Y. Wu, A. Kumar, F. Giraldo, and D. S. Weiss, Stern–gerlach detection of neutral-atom qubits in a state-dependent optical lattice, Nat. Phys. 15, 538 (2019).
  67. M. A. Norcia, W. B. Cairncross, K. Barnes et al., Midcircuit qubit measurement and rearrangement in a Yb171 atomic array, Phys. Rev. X 13, 041034 (2023).
  68. Y. Wu, S. Kolkowitz, S. Puri, and J. D. Thompson, Erasure conversion for fault-tolerant quantum computing in alkaline earth Rydberg atom arrays, Nat. Commun. 13, 4657 (2022).
  69. Matthew N. H. Chow, V. Buchemmavari, S. Omanakuttan, B. J. Little, S. Pandey, I. H. Deutsch, and Y.-Y. Jau, Circuit-based leakage-to-erasure conversion in a neutral-atom quantum processor, PRX Quantum 5, 040343 (2024).
  70. C.-C. Yu, Z.-H. Chen, Y.-H. Deng, M.-C. Chen, C.-Y. Lu, and J.-W. Pan, Processing and decoding Rydberg decay error with MBQC, arXiv:2411.04664.
  71. H. Perrin, S. Jandura, and G. Pupillo, Quantum error correction resilient against atom loss, Quantum 9, 1884 (2025).
  72. S. J. Masson, J. P. Covey, S. Will, and A. Asenjo-Garcia, Dicke superradiance in ordered arrays of multilevel atoms, PRX Quantum 5, 010344 (2024).
  73. P. Scholl, M. Schuler, H. J. Williams, A. A. Eberharter, D. Barredo, K.-N. Schymik, V. Lienhard, L.-P. Henry, T. C. Lang, T. Lahaye, A. M. Läuchli, and A. Browaeys, Quantum simulation of 2D antiferromagnets with hundreds of Rydberg atoms, Nature (London) 595, 233 (2021).
  74. S. Ebadi, T. T. Wang, H. Levine, A. Keesling, G. Semeghini, A. Omran, D. Bluvstein, R. Samajdar, H. Pichler, W. W. Ho, S. Choi, S. Sachdev, M. Greiner, V. Vuletić, and M. D. Lukin, Quantum phases of matter on a 256-atom programmable quantum simulator, Nature (London) 595, 227 (2021).
  75. A. Senoo, A. Baumgärtner, J. W. Lis, G. M. Vaidya, Z. Zeng, G. Giudici, H. Pichler, and A. M. Kaufman, High-fidelity entanglement and coherent multi-qubit mapping in an atom array, arXiv:2506.13632.
  76. 10.17617/3.54NPNY.

Outline

Information

Phys. Rev. Lett. 136, 153602– Published 16 April, 2026
  • Received 12 June 2025
  • Revised 18 December 2025
  • Accepted 16 March 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. Open access publication funded by the Max Planck Society.

Published by the American Physical Society

Sign In to Your Journals Account

Filter

Filter

Article Lookup

Enter a citation