Leaders
Most accurate: Helios (Quantinuum) · not ranked last month
Error-corrected qubits: Helios (Quantinuum) · not ranked last month
Most qubits: Ytterbium atom array (Atom Computing) · not ranked last month
Fastest: Nighthawk r2 (IBM) · not ranked last month
Use it today: Nighthawk r2 (IBM) · not ranked last month
Most accurate: Helios (Quantinuum) · not ranked last month
Error-corrected qubits: Helios (Quantinuum) · not ranked last month
Most qubits: Ytterbium atom array (Atom Computing) · not ranked last month
Fastest: Nighthawk r2 (IBM) · not ranked last month
Use it today: Nighthawk r2 (IBM) · not ranked last month
Home › Rankings › Error-corrected qubits
Logical qubits demonstrated
Error-corrected qubits
Error-corrected ("logical") qubits are built from many physical qubits working together to catch and fix errors. Higher is better.
Why it matters
Error correction is the road from fragile experiments to reliable machines. How many logical qubits a team can run at once is a direct measure of progress on that road.
Keep in mind
A logical qubit can mean different things depending on the error-correction method and how long it was kept running. We only compare results QubitBenchmark has grouped as comparable.
Logical qubits demonstrated. Ranked on grade A and B evidence only. Data: QubitBenchmark release 2026-11.1.
| # | Move | Machine | Type | Result | Grade | Measured | Evidence |
|---|
| 1 | · not ranked last month |
HeliosQuantinuum |
Trapped ion |
48 logical qubits |
B |
Feb 2026 |
Evidence → |
Compared within one method, as grouped by QubitBenchmark: logical-qubit-count@error-corrected. This is the first ranking, so movement shows from next month. Equal results share a place.
Not ranked this month
Results for this measure that don't count here, and why. We show them so nothing is hidden.
| Machine | Grade | Why it isn't ranked | Evidence |
|---|
| Harvard–MIT rubidium atom array QuEra Computing | B | Measured a different way, so not comparable here | Record → |
| Ytterbium atom array Atom Computing | B | Measured a different way, so not comparable here | Record → |
| Cesium atom array Infleqtion | B | Measured a different way, so not comparable here | Record → |
How others rank this
Other organisations' rankings, credited. They don't change ours.
DARPA (US Defense Advanced Research Projects Agency) · 2026-10-07
Ranks: companies
DARPA's QBI tests whether a company's plan for a useful, fault-tolerant quantum computer could be built and run as intended by 2033. Companies pass through Stage A (a concept), Stage B (a year-long review of R&D plans and risk-reduction prototypes) and Stage C, where a government evaluation team tests whether the proposed utility-scale system works as designed. Selections are announced on staggered timelines, and DARPA expects more teams to advance.
- Atom Computing, entered Stage C (neutral atoms)
- Diraq, entered Stage C (silicon CMOS spin qubits)
- IBM, entered Stage C (modular superconducting)
- IonQ, entered Stage C (trapped ions)
- Microsoft and PsiQuantum, already in the equivalent final phase via the US2QC pilot (6 teams in total)
- Who's behind it
- Run by a US government agency with a government verification team. Participants are vendors in a government programme, not submitters to a public leaderboard. DARPA says QBI is not meant to pick a few winners, and that each approach is judged on its own merits.
- How much weight to give it
- An authoritative government selection, but it assesses plans and their feasibility, not measured performance, and the October 2026 announcement says nothing about the other seven Stage B companies.
Free · Read it at DARPA (US Defense Advanced Research Projects Agency) →
Jülich Supercomputing Centre authors (J. A. Montanez-Barrera, Kristel Michielsen); arXiv preprint · 2026-10-05
Ranks: machines
The authors built a low-shot test of the building blocks that error correction needs: parity extraction, mid-circuit measurement, reset, feed-forward and scheduling. They ran it on 10 commercial processors from Quantinuum, IBM and IQM, including circuits shaped like surface codes, colour codes and qLDPC codes. Signal decay is converted into an effective hardware error rate so the machines can be compared. On ibm_phoenix the score correlated with a real logical-memory experiment.
- Quantinuum (Helios-1, H2-1), best overall across tested QEC primitives (effective hardware error), λeff about 0.22% to 0.49% (IBM about 1.1% to 3.2%)
- Quantinuum Helios, hardware error vs top superconducting processors tested, about 13x lower at 30 data qubits; about 8x lower at 50 data qubits
- Quantinuum, 91-data-qubit triangular colour code signal, r = 0.733
- Who's behind it
- Academic (Jülich) authors and no vendor co-authors listed on the abstract page. Funding and hardware access are not described in the pages opened. Quantum Computing Report's article links to a Quantinuum blog post about the result.
- How much weight to give it
- Very recent preprint, not yet peer reviewed; the per-device numbers were read from a trade-press summary, not from the paper itself.
Free · Read it at Jülich Supercomputing Centre authors (J. A. Montanez-Barrera, Kristel Michielsen); arXiv preprint →
DARPA (US Defense Advanced Research Projects Agency) · 2025-11-06
Ranks: companies
In this list, DARPA names the 11 companies that moved from Stage A (concept descriptions) into Stage B, a year-long review of each company's detailed R&D plan, risks and prototypes toward a utility-scale quantum computer by 2033. Companies that succeed are invited to Stage C for government verification. The page also records that Google Quantum AI joined Stage A in September 2025.
- Atom Computing, Diraq, IBM, IonQ, Nord Quantique, Photonic Inc., Quantinuum, Quantum Motion, QuEra Computing, Silicon Quantum Computing, Xanadu, selected for Stage B (11 companies, unranked)
- Who's behind it
- US government programme with a government verification and validation (IV&V) process. Companies are participants rather than paying submitters. DARPA says multiple, a single, or no participants may show a viable path.
- How much weight to give it
- An official list of who advanced, not a ranking; it partly rests on plans and roadmaps, and Stage C has since narrowed it (see darpa-qbi-stage-c-2026).
Free · Read it at DARPA (US Defense Advanced Research Projects Agency) →
