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    Trapped-ion qubits

    Also known as ion-trap quantum computing, trapped ions

    Trapped-ion quantum computers hold individual charged atoms in electromagnetic fields and control them with lasers or microwaves.[1] They report the highest two-qubit gate fidelities of any platform - 99.921% on Quantinuum's Helios and 99.99% in an IonQ result - and Helios has run dozens of logical qubits.[2][3][4]

    Editor reviewedUpdated Quantum computingComputingPhysics
    Key facts

    How they work

    A trapped-ion machine suspends individual charged atoms in electromagnetic fields and uses microwave signals and lasers to encode information in them and perform gates.[1] Quantinuum says the approach offers high fidelities and longer coherence times than other technologies.[5] DARPA describes Quantinuum’s design as a trapped-ion quantum charge-coupled device (QCCD) architecture.[6] IonQ’s Electronic Qubit Control technology drives qubits with precision electronics on semiconductor chips instead of lasers.[3] IonQ says that putting all the control components on classical chips lets it build machines in existing semiconductor fabs.[7]

    Strengths and weaknesses

    Trapped ions lead on accuracy. Quantinuum’s Helios reports 99.921% two-qubit and 99.9975% single-qubit gate fidelity, with all 98 qubits fully connected.[2] IonQ reported 99.99% two-qubit fidelity in October 2025, beating the previous record of 99.97% set in 2024 by Oxford Ionics, which IonQ had since bought.[3][8] Full connectivity allows compact error-correcting codes: Quantinuum used iceberg and concatenated codes to report 48 error-corrected logical qubits from 98 physical qubits.[4] The open challenge is scale. The largest commercial trapped-ion machine has 98 qubits, against thousands of atoms in neutral-atom arrays.[9][10] IonQ’s plan to scale relies on chip manufacturing: Oxford Ionics, now part of IonQ, builds its ion traps on standard semiconductor chips, and IonQ’s electronic control is designed to be made in existing fabs.[11][7]

    Who builds them

    • Quantinuum, based in Broomfield, Colorado, launched Helios commercially in November 2025.[6][9] Its ion trap was manufactured by Honeywell, and programs are written in Guppy, a Python-based language that mixes quantum and classical steps.[12][13] Early users include Amgen, BMW Group, JPMorganChase and SoftBank Corp., working on biologics, catalysts, finance and battery materials.[14][15]
    • IonQ agreed in June 2025 to buy Oxford Ionics, a UK firm that builds ion traps on standard semiconductor chips, for $1.075 billion.[11] Its record-setting 99.99% result came from R&D prototypes that it says underpin 256-qubit systems due to be demonstrated in 2026.[7] Its roadmap targets 256 physical qubits at 99.99% accuracy in 2026, more than 10,000 in 2027 and 2 million by 2030.[16]

    Milestones and outlook

    Quantinuum’s March 2026 logical-qubit results showed logical gate errors near one in ten thousand, better than the underlying physical gates, though described as partially rather than fully fault-tolerant.[4][17] Its preprint reported beyond-break-even performance on benchmarks using between 48 and 94 logical qubits, and the company used 64 logical qubits to simulate quantum magnetism.[18][19] Error correction also needs fast classical computing: Quantinuum said Helios would use NVIDIA‘s CUDA-Q platform for real-time error correction.[20] Both Quantinuum and IonQ entered DARPA’s Quantum Benchmarking Initiative Stage B in November 2025; IonQ advanced to the final Stage C in October 2026, while Quantinuum was not among that round’s four advancers.[21][22] DARPA says it expects further promotions to Stage C.[23] Whether IonQ meets its 256-qubit target for 2026 is a near-term marker to watch.[16] DARPA lists IonQ, based in College Park, Maryland, as its trapped-ion entrant in Stage C, where government evaluators test whether a proposed system can be built and run as designed.[24][25]

    Questions readers ask

    How do trapped-ion quantum computers work?

    They trap charged atoms with electromagnetic fields and encode and manipulate information in them using microwave signals and lasers.[1]

    Which companies build trapped-ion quantum computers?

    The best-known are Quantinuum, maker of Helios, and IonQ, which agreed in 2025 to buy Oxford Ionics.[9][11]

    What is the main advantage of trapped ions?

    High fidelity and long coherence. Quantinuum reports 99.921% two-qubit gate fidelity on Helios.[5][2]

    Sources

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

    1. [1]

      Trapped-ion quantum computers hold charged atoms (ions) in electromagnetic fields and manipulate and encode information in them with microwave signals and lasers. confirmedas of 2026-10-10

    2. [2]

      Quantinuum reports Helios two-qubit gate fidelity of 99.921% and single-qubit gate fidelity of 99.9975%, with all 98 qubits fully connected. confirmedas of 2026-10-10

    3. [3]

      In October 2025 IonQ reported 99.99% two-qubit gate fidelity using its Electronic Qubit Control technology, which drives qubits with precision electronics instead of lasers. confirmedas of 2025-10-21

    4. [4]

      In March 2026 Quantinuum researchers reported computations with up to 94 error-detected and 48 error-corrected logical qubits on Helios, using iceberg and concatenated codes, with logical gate errors around one in ten thousand - better than the physical gates. confirmedas of 2026-03-10

    5. [5]

      Quantinuum says trapped-ion qubits offer high fidelities and longer coherence times than other technologies. confirmedas of 2026-10-10

    6. [6]

      DARPA lists Quantinuum, based in Broomfield, Colorado, as pursuing a trapped-ion quantum charge-coupled device (QCCD) architecture. confirmedas of 2025-11-06

    7. [7]

      IonQ says its Electronic Qubit Control integrates qubit-control components onto classical semiconductor chips, so its machines can be made in existing semiconductor fabs; its 99.99% result came from R&D prototypes that underpin 256-qubit systems due to be demonstrated in 2026. confirmedas of 2025-10-21

    8. [8]

      IonQ said its 99.99% two-qubit result beat the previous record of 99.97%, set in 2024 by Oxford Ionics, which IonQ had since acquired. confirmedas of 2025-10-21

    9. [9]

      Quantinuum launched its Helios trapped-ion computer commercially on 5 November 2025; it uses 98 barium-ion qubits. confirmedas of 2025-11-05

    10. [10]

      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

    11. [11]

      IonQ agreed on 9 June 2025 to acquire Oxford Ionics, a UK trapped-ion company that builds ion traps on standard semiconductor chips, for $1.075 billion, mostly in IonQ stock. confirmedas of 2025-06-09

    12. [12]

      Quantinuum says the Helios ion trap was manufactured by Honeywell. confirmedas of 2025-11-05

    13. [13]

      Quantinuum says Helios has a real-time control engine and a Python-based programming language, Guppy, that lets developers combine quantum and classical computation in a single program. confirmedas of 2025-11-05

    14. [14]

      Helios is offered through Quantinuum's cloud service and on premises, and Quantinuum named Amgen, BMW Group, JPMorganChase and SoftBank Corp. among its initial enterprise customers. confirmedas of 2025-11-05

    15. [15]

      Quantinuum said its early Helios users include Amgen exploring hybrid quantum machine learning for biologics, BMW Group researching fuel-cell catalyst materials, JPMorganChase researching financial analytics and SoftBank Corp. exploring organic materials for batteries and solar cells. confirmedas of 2025-11-05

    16. [16]

      IonQ's post-merger roadmap targets 256 physical qubits at 99.99% accuracy in 2026, more than 10,000 physical qubits in 2027 and 2 million physical qubits by 2030. confirmedas of 2025-06-09

    17. [17]

      The March 2026 Quantinuum results were described as partially rather than fully fault-tolerant computation. confirmedas of 2026-03-10

    18. [18]

      The Quantinuum preprint reports beyond-break-even performance across both fault-tolerant and partially fault-tolerant benchmarks using between 48 and 94 logical qubits. confirmedas of 2026-02-25

    19. [19]

      Quantinuum said it used 64 of its logical qubits on Helios to simulate quantum magnetism at a scale that can be very difficult for classical computers, and that its logical qubits beat their physical counterparts. confirmedas of 2026-03-04

    20. [20]

      At the Helios launch Quantinuum said it would integrate NVIDIA GB200 systems with Helios through NVIDIA NVQLink and switch to NVIDIA accelerated computing, using its Guppy language with the NVIDIA CUDA-Q platform for real-time error correction. confirmedas of 2025-11-05

    21. [21]

      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

    22. [22]

      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

    23. [23]

      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

    24. [24]

      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

    25. [25]

      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

    Revision history (2)
    1. Page created.
    2. Added primary sources for Quantinuum's logical-qubit results, IonQ's chip-based control and prior fidelity record, and Helios's NVIDIA error-correction link.

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

    Cite this page

    "Trapped-ion qubits." ContentLora, updated Oct 10, 2026. https://contentlora.com/wiki/trapped-ion-qubits

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