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Universal Neutral-Atom Quantum Computer with Individual Optical Addressing and Nondestructive Readout

A.G. Radnaev1,*, W.C. Chung1,*, D.C. Cole1,*, D. Mason1,*, T.G. Ballance4, M.J. Bedalov2, D.A. Belknap2, M.R. Berman1, M. Blakely2 et al.

I.L. Bloomfield1, P.D. Buttler1, C. Campbell3, A. Chopinaud4, E. Copenhaver1, M.K. Dawes1, S.Y. Eubanks1, A.J. Friss1, D.M. Garcia1, J. Gilbert1, M. Gillette2, P. Goiporia3, P. Gokhale3, J. Goldwin2, D. Goodwin2, T.M. Graham5, C.J. Guttormsson1, G.T. Hickman1, L. Hurtley2, M. Iliev1, E.B. Jones1, R.A. Jones1, K.W. Kuper1, T.B. Lewis1, M.T. Lichtman2, F. Majdeteimouri1, J.J. Mason2, J.K. McMaster1, J.A. Miles2, P.T. Mitchell1, J.D. Murphree2, N.A. Neff-Mallon2, T. Oh1, V. Omole3, C. Parlo Simon1, N. Pederson2, M.A. Perlin3, A. Reiter1, R. Rines3, P. Romlow2, A.M. Scott1, D. Stiefvater1, J.R. Tanner1, A.K. Tucker1, I.V. Vinogradov1, M.L. Warter1, M. Yeo1, M. Saffman2,5, and T.W. Noel1,†

  • *These authors contributed equally to this work.
  • †Contact author: tom.noel@infleqtion.com
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PRX Quantum 6, 030334 – Published 25 August, 2025

DOI: https://doi.org/10.1103/66s8-jj18

Abstract

Quantum computers must achieve large-scale fault-tolerant operation to deliver on their promise of transformational processing power. This will require thousands or millions of high-fidelity quantum gates and similar numbers of qubits. Demonstrations using neutral-atom qubits trapped and manipulated by lasers have shown that this modality can provide high two-qubit gate (cz) fidelities and scalable operation. However, the gates in these demonstrations are driven by lasers that do not resolve individual qubits, with universal computation enabled by physical midcircuit shuttling of the qubits. This relatively slow operation may greatly extend run times for useful large-scale computation. Here, we demonstrate a universal neutral-atom quantum computer with gate rates limited by optical switching times, rather than shuttling, by individually addressing tightly focused laser beams at an array of single atoms. We achieve cz fidelity of 99.35(4)% and local single-qubit RZ gate fidelity of 99.902(8)%  in both cases accounting for leakage out of the computational basis. Moreover, we demonstrate nondestructive readout of alkali-atom qubits with 0.9(3)% loss, which boosts operational speed. This technique also enables us to measure a state-of-the-art cz fidelity of 99.73(3)% when excluding atom-loss events, which may be mitigated through erasure conversion. Our results represent a critical step toward large-scale fault-tolerant neutral-atom quantum computers that can execute computations on practical timescales.

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Physics Subject Headings (PhySH)

Popular Summary

Quantum computers promise to solve certain problems faster than classical computers, but to achieve this, they must operate fault tolerantly, scale up to a very large number of physical qubits, and compute within a practical time. Our research demonstrates progress on a new kind of neutral-atom quantum computer that takes a major step toward this goal by using tightly focused laser beams to control individual atoms. This method allows us to perform high-speed quantum logic operations between neighboring qubits with high fidelity and eliminates the need to move atoms to perform each entangling gate.

Instead, we use fast switchable lasers to perform both single- and two-qubit operations on static atoms. Gate rates can be significantly increased as a result. We achieve an entangling gate fidelity of 99.35(4)% [99.73(3)% when enabling an atom-loss filter] and single-qubit fidelities at 99.9%, surpassing thresholds for quantum error correction. A major innovation in our design is the use of nondestructive readout, which lets us measure qubit states without losing the atoms, enabling repeated measurements and faster computation—similar to reusing rocket boosters.

Our system demonstrates key ingredients for a scalable path toward sufficiently fast fault-tolerant quantum computers. Future improvements—parallel gate operations, scaling to thousands of qubits, and quantum error correction with midcircuit measurements—will further accelerate performance. This platform provides a compelling foundation for practical quantum computing, bringing us closer to solving real-world problems in fields such as materials science, medicine, and cryptography.

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References (74)

  1. P. W. Shor, in Proceedings—Annual IEEE Symposium on Foundations of Computer Science, FOCS (IEEE, Santa Fe, NM, USA, 1994), p. 124.
  2. S. McArdle, S. Endo, A. Aspuru-Guzik, S. C. Benjamin, and X. Yuan, Quantum computational chemistry, Rev. Mod. Phys. 92, 015003 (2020).
  3. X. Gao, E. R. Anschuetz, S. T. Wang, J. I. Cirac, and M. D. Lukin, Enhancing generative models via quantum correlations, Phys. Rev. X 12, 021037 (2022).
  4. R. Santagati, A. Aspuru-Guzik, R. Babbush, M. Degroote, L. González, E. Kyoseva, N. Moll, M. Oppel, R. M. Parrish, N. C. Rubin, M. Streif, C. S. Tautermann, H. Weiss, N. Wiebe, and C. Utschig-Utschig, Drug design on quantum computers, Nat. Phys. 20, 549 (2024).
  5. P. Date, D. Arthur, and L. Pusey-Nazzaro, QUBO formulations for training machine learning models, Sci. Rep. 11, 1 (2021).
  6. H. Ma, M. Govoni, and G. Galli, Quantum simulations of materials on near-term quantum computers, npj Comput. Mater. 6, 1 (2020).
  7. S. Koretsky et al., in Proceedings—2021 IEEE International Conference on Quantum Computing and Engineering, QCE 2021 (IEEE, Broomfield, CO, USA, 2021), p. 181.
  8. M. A. Perlin et al., Q-CHOP: Quantum constrained Hamiltonian optimization, Arxiv:2403.05653v1.
  9. S. Ramesh, T. Tomesh, S. J. Riesenfeld, F. T. Chong, and A. T. Pearson, Quantum computing for oncology, Nat. Cancer 5, 811 (2024).
  10. T. Hoefler, T. Häner, and M. Troyer, Disentangling hype from practicality: On realistically achieving quantum advantage, Commun. ACM 66, 82 (2023).
  11. D. Bluvstein et al., Logical quantum processor based on reconfigurable atom arrays, Nature 626, 58 (2024).
  12. P. S. Rodriguez, J. M. Robinson, P. N. Jepsen, Z. He, C. Duckering, C. Zhao, K.-H. Wu, J. Campo, K. Bagnall, M. Kwon et al., Experimental demonstration of logical magic state distillation, Nature (2025).
  13. B. W. Reichardt et al., Logical computation demonstrated with a neutral atom quantum processor, ArXiv:2411.11822.
  14. G. Q. AI, Suppressing quantum errors by scaling a surface code logical qubit, Nature 614, 676 (2023).
  15. M. P. da Silva et al., Demonstration of logical qubits and repeated error correction with better-than-physical error rates, Arxiv:2404.02280v2.
  16. M. Bedalov et al., Fault-tolerant operation and materials science with neutral atom logical qubits, ArXiv:2412.07670.
  17. J. Bergou, M. Hillery, and M. Saffman, Quantum Information Processing: Theory and Implementation (Springer, Cham, Switzerland, 2021), 2nd ed.
  18. H. J. Manetsch, G. Nomura, E. Bataille, K. H. Leung, X. Lv, and M. Endres, A tweezer array with 6100 highly coherent atomic qubits, arxiv:2403.12021v2.
  19. T. M. Graham et al., Multi-qubit entanglement and algorithms on a neutral-atom quantum computer, Nature 604, 457 (2022).
  20. M. Peper, Y. Li, D. Y. Knapp, M. Bileska, S. Ma, G. Liu, P. Peng, B. Zhang, S. P. Horvath, A. P. Burgers, and J. D. Thompson, Spectroscopy and modeling of 171Yb Rydberg states for high-fidelity two-qubit gates, Phys. Rev. X 15, 011009 (2025).
  21. 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 634, 321 (2024), https://www.nature.com/articles/s41586-024-08005-8.
  22. T. Y. Wu, Neutral-atom quantum computer with 87Sr nuclear-spin qubits (2024). https://meetings.aps.org/Meeting/DAMOP24/Session/J06.3.
  23. M. Saffman, T. G. Walker, and K. Mølmer, Quantum information with Rydberg atoms, Rev. Mod. Phys. 82, 2313 (2010).
  24. 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 622, 268 (2023).
  25. J. Muniz, M. Stone, D. T. Stack, M. Jaffe, J. M. Kindem, L. Wadleigh, E. Zalys-Geller, X. Zhang, C.-A. Chen, M. A. Norcia et al., High-fidelity universal gates in the 171Yb ground-state nuclear-spin qubit, PRX Quantum 6, 020334 (2025).
  26. S. Jandura and G. Pupillo, Time-optimal two- and three-qubit gates for Rydberg atoms, Quantum 6, 712 (2022), https://quantum-journal.org/papers/q-2022-05-13-712/.
  27. M. A. Norcia et al., Iterative assembly of 171Yb atom arrays with cavity-enhanced optical lattices, PRX Quantum 5, 030316 (2024).
  28. P. Huft, Y. Song, T. M. Graham, K. Jooya, S. Deshpande, C. Fang, M. Kats, and M. Saffman, Simple, passive design for large optical trap arrays for single atoms, Phys. Rev. A 105, 063111 (2022).
  29. D. B. Tan, D. Bluvstein, M. D. Lukin, and J. Cong, Compiling quantum circuits for dynamically field-programmable neutral atoms array processors, Quantum 8, 1281 (2024).
  30. M. R. Lam, N. Peter, T. Groh, W. Alt, C. Robens, D. Meschede, A. Negretti, S. Montangero, T. Calarco, and A. Alberti, Demonstration of quantum brachistochrones between distant states of an atom, Phys. Rev. X 11, 011035 (2021).
  31. C. Poole, T. M. Graham, M. A. Perlin, M. Otten, and M. Saffman, Architecture for fast implementation of qLDPC codes with optimized Rydberg gates, arxiv:2404.18809v1.
  32. E. Knill, Quantum computing with realistically noisy devices, Nature 434, 39 (2005).
  33. 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).
  34. S. Bravyi, A. W. Cross, J. M. Gambetta, D. Maslov, P. Rall, and T. J. Yoder, High-threshold and low-overhead fault-tolerant quantum memory, Nature 627, 778 (2024).
  35. Y. Hong, M. Marinelli, A. M. Kaufman, and A. Lucas, Long-range-enhanced surface codes, Phys. Rev. A 110, 022607 (2024).
  36. via Infleqtion Superstaq [39].
  37. Infleqtion PICAS.
  38. T. M. Graham, E. Oh, and M. Saffman, Multiscale architecture for fast optical addressing and control of large-scale qubit arrays, Appl. Opt. 62, 3242 (2023).
  39. C. Campbell et al., in 2023 IEEE International Conference on Quantum Computing and Engineering (QCE) (IEEE, Bellevue, WA, USA, 2023), p. 1020.
  40. C. Tuchendler, A. M. Lance, A. Browaeys, Y. R. P. Sortais, and P. Grangier, Energy distribution and cooling of a single atom in an optical tweezer, Phys. Rev. A 78, 033425 (2008).
  41. S. Kuhr, W. Alt, D. Schrader, I. Dotsenko, Y. Miroshnychenko, A. Rauschenbeutel, and D. Meschede, Analysis of dephasing mechanisms in a standing-wave dipole trap, Phys. Rev. A 72, 023406 (2005).
  42. C. H. Baldwin, B. J. Bjork, J. P. Gaebler, D. Hayes, and D. Stack, Subspace benchmarking high-fidelity entangling operations with trapped ions, Phys. Rev. Res. 2, 013317 (2020).
  43. K. Barnes et al., Assembly and coherent control of a register of nuclear spin qubits, Nat. Commun. 13, 1 (2022).
  44. 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 622, 279 (2023).
  45. 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).
  46. J. Preskill, Reliable quantum computers, Proc.: Math. Phys. Eng. Sci. 454, 385 (1998).
  47. M. 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).
  48. 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).
  49. 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).
  50. J. P. Covey, H. Weinfurter, and H. Bernien, Quantum networks with neutral atom processing nodes, npj Quantum Inf. 9, 90 (2023).
  51. L. Su, A. Douglas, M. Szurek, A. H. Hebert, A. Krahn, R. Groth, G. A. Phelps, O. Marković, and M. Greiner, Fast single atom imaging for optical lattice arrays, Nature 16 (2025).
  52. T. M. Graham, L. Phuttitarn, R. Chinnarasu, Y. Song, C. Poole, K. Jooya, J. Scott, A. Scott, P. Eichler, and M. Saffman, Midcircuit measurements on a single-species neutral alkali atom quantum processor, Phys. Rev. X 13, 041051 (2023).
  53. S. Jandura, J. D. Thompson, and G. Pupillo, Optimizing Rydberg gates for logical-qubit performance, PRX Quantum 4, 020336 (2023).
  54. M. Mohan, R. de Keijzer, and S. Kokkelmans, Robust control and optimal rydberg states for neutral atom two-qubit gates, Phys. Rev. Res. 5, 033052 (2023).
  55. I. Christen, T. Propson, M. Sutula, H. Sattari, G. Choong, C. Panuski, A. Melville, J. Mallek, C. Brabec, S. Hamilton, P. Benjamin Dixon, A. J. Menssen, D. Braje, A. H. Ghadimi, and D. Englund, An integrated photonic engine for programmable atomic control, Nat. Commun. 16, 82 (2025).
  56. K.-N. Schymik, B. Ximenez, E. Bloch, D. Dreon, A. Signoles, F. Nogrette, D. Barredo, A. Browaeys, and Th. Lahaye, In situ equalization of single-atom loading in large-scale optical tweezer arrays, Phys. Rev. A 106, 022611 (2022).
  57. M. E. Shea, P. M. Baker, J. A. Joseph, J. Kim, and D. J. Gauthier, Submillisecond, nondestructive, time-resolved quantum-state readout of a single, trapped neutral atom, Phys. Rev. A 102, 053101 (2020).
  58. M. N. Chow, B. J. Little, and Y. Y. Jau, High-fidelity low-loss state detection of alkali-metal atoms in optical tweezer traps, Phys. Rev. A 108, 032407 (2023).
  59. I. D. Kivlichan, C. Gidney, D. W. Berry, N. Wiebe, J. McClean, W. Sun, Z. Jiang, N. Rubin, A. Fowler, A. Aspuru-Guzik, H. Neven, and R. Babbush, Improved fault-tolerant quantum simulation of condensed-phase correlated electrons via Trotterization, Quantum 4, 296 (2020).
  60. E. T. Campbell, Early fault-tolerant simulations of the Hubbard model, Quantum Sci. Technol. 7, 015007 (2021).
  61. S. Anand, C. E. Bradley, R. White, V. Ramesh, K. Singh, and H. Bernien, A dual-species Rydberg array, Nat. Phys. 20, 1744 (2024), https://www.nature.com/articles/s41567-024-02638-2.
  62. K. Singh, C. E. Bradley, S. Anand, V. Ramesh, R. White, and H. Bernien, Mid-circuit correction of correlated phase errors using an array of spectator qubits, Science 380, 1265 (2023).
  63. N. Chen, L. Li, W. Huie, M. Zhao, I. Vetter, C. H. Greene, and J. P. Covey, Analyzing the Rydberg-based optical-metastable-ground architecture for 171Yb nuclear spins, Phys. Rev. A 105, 052438 (2022).
  64. 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).
  65. B. Zhang, P. Peng, A. Paul, and J. D. Thompson, Scaled local gate controller for optically addressed qubits, Optica 11, 227 (2024).
  66. S. Ma, A. P. Burgers, G. Liu, J. Wilson, B. Zhang, and J. D. Thompson, Universal gate operations on nuclear spin qubits in an optical tweezer array of 171Yb atoms, Phys. Rev. X 12, 021028 (2022).
  67. 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 622, 273 (2023).
  68. H. Levine, A. Keesling, G. Semeghini, A. Omran, T. T. Wang, S. Ebadi, H. Bernien, M. Greiner, V. Vuletić, H. Pichler, and M. D. Lukin, Parallel implementation of high-fidelity multiqubit gates with neutral atoms, Phys. Rev. Lett. 123, 170503 (2019).
  69. M. A. Perlin, V. N. Premakumar, J. Wang, M. Saffman, and R. Joynt, Fault-tolerant measurement-free quantum error correction with multiqubit gates, Phys. Rev. A 108, 062426 (2023).
  70. Z. Tian, H. Chang, X. Lv, M. Yang, Z. Wang, P. Yang, P. Zhang, G. Li, and T. Zhang, Resolved Raman sideband cooling of a single optically trapped cesium atom, Opt. Lett. 49, 542 (2024).
  71. B. Nikolov, E. Diamond-Hitchcock, J. Bass, N. L. Spong, and J. D. Pritchard, Randomized benchmarking using nondestructive readout in a two-dimensional atom array, Phys. Rev. Lett. 131, 030602 (2023).
  72. A. Bergschneider, V. M. Klinkhamer, J. H. Becher, R. Klemt, G. Zürn, P. M. Preiss, and S. Jochim, Spin-resolved single-atom imaging of 6Li in free space, Phys. Rev. A 97, 063613 (2018).
  73. I. S. Madjarov, Ph.D. thesis, California Institute of Technology, Pasadena, California, 2021. https://resolver.caltech.edu/CaltechTHESIS:01292021-001639979.
  74. Y.-H. Chen and C. H. Baldwin, Randomized benchmarking with leakage errors, Arxiv:2502.00154.

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PRX Quantum 6, 030334– Published 25 August, 2025
  • Received 19 January 2025
  • Accepted 11 July 2025
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