Catalog — QPU record · Oxford Ionics · Trapped ion
Oxford Ionics QUARTET
Oxford Ionics QUARTET is a trapped ion gate-based processor by Oxford Ionics with 99.99% qubits (2025). Below: every publicly disclosed figure with its source, method, and vendor-claim status — plus what is not disclosed, recorded as findings.
Measurement records2 disclosed · 6 not disclosed · 2 sources
Select a figure to open its record
Availability (device_reality_and_availability)Real, installed device: QUARTET (QUantum Advantage-Ready Trapped-ion Exploration Testbed), a full-stack trapped-ion quantum computer delivered to and installed in the UK NQCC's quantum data centre at Harwell campus; announced 2025-08-13; used in NQCC testbed programme and UK Quantum Missions initiativevendor claim
Vendor claim
- Source
- Oxford Ionics Delivers Quantum Computer to the UK's National Quantum Computing Centre · published 2025-08-13
- Method
- VENDOR_UNSPECIFIED
- Notes
- Field-upgradeable: performance upgrades by swapping the 'credit-card sized Quantum Processor Unit (QPU)'. No public cloud access found.
- Citation key
[oxford-ionics/oxford-ionics-quartet:device-reality-and-avail:2026-08-19]
Qubit count (qubit_count_physical)not publicly disclosed
Not publicly disclosed — checked 2026-08-19
- Finding
- No public disclosure found. This is a recorded, dated finding — we do not substitute an estimate or borrow a figure from a sibling device.
- Sources queried
- oxionics.com delivery announcement, oxionics.com/products (only roadmap targets: 16-64 qubits in 2025, 256+ in 2026, 10000+ in 2027), web search of press coverage (The Quantum Insider, HPCwire, Harwell Campus, Quantum Computing Report) — none states QUARTET's qubit count
- Notes
- Vendor roadmap ranges are targets, not a disclosed count for the installed QUARTET system.
Two-qubit gate quality (two_qubit_gate_fidelity)99.99% %vendor claim
Vendor claim
- Source
- Accelerating Towards Fault Tolerance: Unlocking 99.99% Two-Qubit Gate Fidelities - Oxford Ionics · published 2025-10-21
- Method
- 'Subspace Leakage Error Randomized Benchmarking showing the application of up to 500 sequential Cliffords (1,083 two-qubit gates)'; electronic control without ground-state cooling (operation above the Doppler limit)
- Aggregation
- record/best demonstration ('four nines threshold')
- Notes
- IMPORTANT SCOPE CAVEAT: demonstrated on Oxford Ionics/IonQ chip technology (mass-manufacturable trap chips); the blog does NOT state it was measured on the deployed QUARTET system. Products page separately claims '99.99% two-qubit fidelity' as a platform figure without method. Blog says technical paper released to arXiv same day (not fetched this session). Blog text is IonQ-branded ('IonQ is the first and only quantum computing company to cross the four nines threshold').
- Citation key
[oxford-ionics/oxford-ionics-quartet:two-qubit-gate-fidelity:2026-08-19]
Single-qubit gate quality (one_qubit_gate_fidelity)not publicly disclosed
Not publicly disclosed — checked 2026-08-19
- Finding
- No public disclosure found. This is a recorded, dated finding — we do not substitute an estimate or borrow a figure from a sibling device.
- Sources queried
- oxionics.com/products, delivery announcement, 99.99% blog post
- Notes
- Vendor claims to hold records for single-qubit gate fidelity and SPAM but publishes no numbers for QUARTET on the pages checked.
Coherence (T1_T2_coherence_times)not publicly disclosed
Not publicly disclosed — checked 2026-08-19
- Finding
- No public disclosure found. This is a recorded, dated finding — we do not substitute an estimate or borrow a figure from a sibling device.
- Sources queried
- oxionics.com/products, delivery announcement, blog post
Readout (readout_fidelity)not publicly disclosed
Not publicly disclosed — checked 2026-08-19
- Finding
- No public disclosure found. This is a recorded, dated finding — we do not substitute an estimate or borrow a figure from a sibling device.
- Sources queried
- oxionics.com/products, delivery announcement, blog post
Gate duration (two_qubit_gate_duration)not publicly disclosed
Not publicly disclosed — checked 2026-08-19
- Finding
- No public disclosure found. This is a recorded, dated finding — we do not substitute an estimate or borrow a figure from a sibling device.
- Sources queried
- oxionics.com/products, delivery announcement, blog post
Ion species (ion_species)not publicly disclosed
Not publicly disclosed — checked 2026-08-19
- Finding
- No public disclosure found. This is a recorded, dated finding — we do not substitute an estimate or borrow a figure from a sibling device.
- Sources queried
- oxionics.com/products, delivery announcement, 99.99% fidelity blog post
QPU137 is independent and is not affiliated with, endorsed by, or sponsored by Oxford Ionics. Figures above are public disclosures recorded with their sources on 2026-08-19; vendor claims are labeled as such and may not be directly comparable across measurement methods — see methodology.