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    Neutral-atom qubits

    Also known as cold-atom quantum computing, Rydberg atom qubits, optical tweezer arrays

    Neutral-atom quantum computers hold uncharged atoms in arrays of tightly focused laser beams called optical tweezers and use them as qubits.[1] The approach scaled fastest in 2025-2026: a 6,100-atom array, a 448-atom fault-tolerant architecture and 30 entangled logical qubits on a commercial system.[1][2][3]

    Editor reviewedUpdated Quantum computingComputingPhysics
    Key facts

    How they work

    Neutral-atom machines trap individual uncharged atoms in a vacuum using optical tweezers, tightly focused laser beams. In September 2025 a Caltech team split one laser into 12,000 tweezers holding 6,100 cesium atoms, the largest such array reported; earlier arrays of this kind held only hundreds of qubits.[1][4] Lasers also encode and manipulate the qubits; the Harvard-led group uses rubidium atoms.[2] QuEra says these qubits are naturally identical, operate at room temperature and can be flexibly connected to any other qubit.[5] It adds that its architecture runs many operations in parallel and can host several different error-correcting codes, which it says lowers overhead.[6]

    Strengths and weaknesses

    Neutral atoms scale to large numbers and hold their state for a long time: the Caltech array kept superposition for about 13 seconds, with 99.98% accuracy for individual-qubit operations.[1] Caltech said that coherence time was nearly 10 times longer than in earlier similar arrays.[4] By comparison, Google’s superconducting Willow chip has coherence times approaching 100 microseconds.[7] Atoms can be physically moved hundreds of micrometres without losing superposition, which lets machines rearrange qubits for error correction; Caltech contrasts this with hard-wired platforms such as superconducting qubits.[8] The Caltech team had not yet entangled its 6,100 atoms in a full computation, so size alone is not computing power; entangling them was its planned next step, and it described error correction across thousands of physical qubits as the field’s next big milestone.[1][9] Researchers also say many technical challenges remain before machines with millions of qubits.[10]

    Landmark results

    • 448-atom fault-tolerant architecture (November 2025). Harvard, MIT and QuEra reported in Nature a system combining all the essential elements of scalable error-corrected computation, with errors below threshold.[2] It combined physical entanglement, logical entanglement, “logical magic” and entropy removal, using tricks such as quantum teleportation, in circuits with dozens of error-correction layers.[11] Below threshold means adding qubits reduces errors rather than increasing them, and the lead author called it the first conceptually scalable architecture.[12]
    • 6,100-atom array (September 2025). Caltech’s record array, published in Nature.[1]
    • 30 logical qubits (September 2026). Infleqtion reported entangling 30 logical qubits encoded in 80 physical qubits on its commercial Sqale system, in a circuit of about 1,000 operations.[3] The company calls that scale 1 KiloQuOp and says the result validated the joint design of its Sqale hardware and Superstaq software; it is a company-reported result.[13]

    Who builds them

    QuEra Computing, a Harvard-MIT spinout, and Atom Computing both entered DARPA’s Quantum Benchmarking Initiative Stage B in November 2025.[14][2] Atom Computing, based in Boulder, Colorado, advanced to the final Stage C in October 2026 with what DARPA describes as scalable arrays of neutral atoms; QuEra did not advance in that round.[15][16] In Stage C, DARPA’s evaluators test whether a proposed utility-scale system can be built and operated as designed.[17] DARPA says it expects more companies to advance to Stage C.[18] Infleqtion says it targets 100 logical qubits by 2028.[3] For how neutral atoms compare with other approaches, see how qubits work.

    Questions readers ask

    How are neutral-atom qubits held in place?

    By optical tweezers, highly focused laser beams. Caltech's record array split one laser into 12,000 tweezers holding 6,100 atoms.[1]

    Do neutral-atom machines need to be cooled to near absolute zero?

    QuEra says its neutral-atom qubits operate at room temperature, unlike superconducting qubits that need dilution refrigerators.[5][20]

    Have neutral atoms shown error correction?

    Yes. Harvard, MIT and QuEra reported a 448-atom architecture that suppressed errors below threshold, and Infleqtion reported 30 entangled logical qubits in 2026.[2][3]

    Sources

    Each numbered claim is a statement we checked against the sources listed with it. Status shows how well established it is.

    1. [1]

      In September 2025 a Caltech team reported in Nature an array of 6,100 cesium-atom qubits held by optical tweezers (one laser split into 12,000 tweezers), with superposition lasting about 13 seconds and 99.98% accuracy in manipulating individual qubits; entangling the qubits for full computations was the stated next step. confirmedas of 2025-09-24

    2. [2]

      In November 2025 Harvard, MIT and QuEra researchers reported in Nature an architecture using up to 448 rubidium-atom qubits that combined the essential elements of scalable error-corrected computation and suppressed errors below the threshold. confirmedas of 2025-11-12

    3. [3]

      On 24 September 2026 Infleqtion reported entangling 30 logical qubits encoded in 80 physical neutral-atom qubits on its Sqale system, in a circuit of about 1,000 physical operations, and said it targets 100 logical qubits by 2028. reportedas of 2026-09-24

    4. [4]

      Caltech said previous neutral-atom arrays of this kind held only hundreds of qubits, and that its 13-second superposition was nearly 10 times longer than in earlier similar arrays. confirmedas of 2025-09-24

    5. [5]

      QuEra says its neutral-atom systems use naturally identical qubits that operate at room temperature with flexible all-to-all connectivity. confirmedas of 2025-11-06

    6. [6]

      QuEra says its architecture supports highly parallel operations and multiple quantum error-correction codes, which it says reduces overhead. confirmedas of 2025-11-06

    7. [7]

      Willow's qubits have T1 coherence times approaching 100 microseconds, about five times longer than Google's previous generation. confirmedas of 2024-12-09

    8. [8]

      The Caltech team showed atoms could be moved hundreds of micrometres while keeping their superposition, a capability useful for error correction in neutral-atom systems. confirmedas of 2025-09-24

    9. [9]

      Caltech described the field's next big milestone as quantum error correction at the scale of thousands of physical qubits, and its team planned next to entangle the qubits in its array. confirmedas of 2025-09-24

    10. [10]

      The Harvard study's lead author said many technical challenges remain before a very large-scale computer with millions of qubits. confirmedas of 2025-11-12

    11. [11]

      The Harvard-led 448-atom system combined physical entanglement, logical entanglement, logical magic and entropy removal, using techniques such as quantum teleportation, in circuits with dozens of error-correction layers. confirmedas of 2025-11-12

    12. [12]

      Harvard describes the error threshold its 448-atom system crossed as the point where adding qubits further reduces errors rather than increasing them, and the lead author called it the first conceptually scalable architecture. confirmedas of 2025-11-12

    13. [13]

      Infleqtion said its 30-logical-qubit experiment executed about 1,000 physical operations, which it calls 1 KiloQuOp, and validated the co-design of its Sqale hardware and Superstaq software. reportedas of 2026-09-24

    14. [14]

      On 6 November 2025 DARPA moved 11 companies to QBI Stage B - Atom Computing, Diraq, IBM, IonQ, Nord Quantique, Photonic, Quantinuum, Quantum Motion, QuEra, Silicon Quantum Computing and Xanadu. confirmedas of 2025-11-06

    15. [15]

      DARPA lists the October 2026 Stage C entrants as Atom Computing of Boulder, Colorado (neutral-atom arrays), Diraq of Sydney (silicon CMOS spin qubits), IBM of Yorktown Heights, New York (modular superconducting processors) and IonQ of College Park, Maryland (trapped ions). confirmedas of 2026-10-07

    16. [16]

      On 7 October 2026 DARPA advanced Atom Computing, Diraq, IBM and IonQ to QBI Stage C, joining Microsoft and PsiQuantum, which entered from the US2QC pilot. confirmedas of 2026-10-07

    17. [17]

      QBI runs in three stages - Stage A, a six-month system concept study; Stage B, a deeper risk-reduction and R&D planning stage; and Stage C, government verification and validation of hardware. confirmedas of 2026-03-10

    18. [18]

      DARPA said QBI had evaluated more than 20 companies since its mid-2024 launch, that Quandela joined Stage A in May 2026, and that it expects more companies to advance to Stage C. confirmedas of 2026-10-07

    19. [19]

      DARPA lists the QBI Stage B approaches as neutral atoms (Atom Computing, QuEra), trapped ions (IonQ, Quantinuum), superconducting circuits (IBM, and Nord Quantique with bosonic error correction), silicon spin or atom qubits (Diraq, Photonic, Quantum Motion, Silicon Quantum Computing) and photonics (Xanadu). confirmedas of 2025-11-06

    20. [20]

      IBM put the first quantum computer on the cloud on 4 May 2016, a five-qubit superconducting device kept in a dilution refrigerator at roughly 15 to 20 millikelvin. confirmedas of 2021-05-04

    Revision history (2)
    1. Page created.
    2. Added scale context for the Caltech array, the mechanisms behind the 448-atom result, QuEra architecture details and DARPA Stage C context.

    Created Oct 10, 2026. Last reviewed by an editor on Oct 10, 2026. Next scheduled review: Jan 10, 2027.

    Cite this page

    "Neutral-atom qubits." ContentLora, updated Oct 10, 2026. https://contentlora.com/wiki/neutral-atom-qubits

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