Quantum/Machines/Reimei
Japan · operational · Trapped ions
Reimei
Reimei is a trapped ions quantum computer operated by RIKEN in Japan. It has 20 physical qubits. It ranks 9 of 15 trapped ion machines in this table by physical qubit count. 9 sourced specs are in the spec sheet. No benchmark figures are recorded for it yet.
Also known as RIKEN-Quantinuum Reimei
Quantinuum trapped-ion computer installed at the RIKEN Wako campus and announced on 2025-02-12, named Reimei (dawn). RIKEN reports a 20-qubit device with a possible upgrade to roughly 50 qubits in coming years. RIKEN states that linking it to Fugaku in Kobe is a planned milestone, so no HPC integration is recorded here.
Spec sheet
Technical details as the builder or a paper states them, each with its own source. A blank is a fact we could not source, not a zero. Fidelity and coherence figures are in the benchmark table below.
| Spec | Value | Basis | Note | Source |
|---|---|---|---|---|
| Processor | Quantinuum System Model H1 family trapped-ion processor, 20 qubits | Peer reviewed | Quantinuum Systems Reference says Reimei belongs to the H1 family; the RIKEN-affiliated paper says Reimei is based on the H-1 series. | docs.quantinuum.comarxiv.org |
| Qubit type | 171Yb+ hyperfine qubits with 138Ba+ coolant ions | Peer reviewed | Family-wide fact from H1-1 and H1-2 papers; Reimei is an H1-family unit and its ion species is not stated in RIKEN material. | arxiv.orgdocs.quantinuum.com |
| Topology | All-to-all connectivity across 20 qubits | Vendor reported | RIKEN quotes all-to-all connectivity; the RIKEN-affiliated paper describes 20 qubits with all-to-all connectivity. | riken.jparxiv.org |
| Native gates | ZZPhase (arbitrary-angle ZZ) two-qubit gates | Peer reviewed | Paper states two-qubit native gates on Reimei are ZZPhase gates in pytket notation; single-qubit native gates are not listed there. | arxiv.org |
| Software | Quantinuum Nexus, pytket | Peer reviewed | Paper ran experiments on Reimei through the Quantinuum Nexus platform and uses pytket gate notation. | arxiv.org |
| Cloud platforms | Quantinuum Nexus | Peer reviewed | Paper accessed Reimei via Nexus; RIKEN research highlight describes using the machines via the cloud. | arxiv.org |
| Access and pricing | On-premises regional deployment at RIKEN Wako campus; also runs customer jobs | Vendor reported | Docs say the Japan instance continues executing customer jobs; installation was commissioned under a NEDO project and announced 2025-02-12. | docs.quantinuum.comquantinuum.com |
| Predecessor | Quantinuum H1 | Vendor reported | Reimei is an H1-family system. | docs.quantinuum.com |
| Roadmap | RIKEN hopes to upgrade to around 50 qubits in the next couple of years; link to Fugaku planned | Vendor reported | RIKEN stated the upgrade hope in an article dated 2025-08-22 and described linking to Fugaku as a milestone on 2025-02-12. | riken.jpriken.jp |
Timeline
- 2025-02: First operational
- 2026-10: Status checked: operational
More from RIKEN
- RIKEN IBM Quantum System Two (operational, 156 qubits)
- RIKEN Fujitsu 256-qubit (operational, 256 qubits)
Comparable trapped ion machines
Closest in physical qubit count within the same technology. Counts of different qubit types are not interchangeable across technologies.
| Machine | Operator | Qubits | Status |
|---|---|---|---|
| Quantinuum H1 | Quantinuum | 20 | upgraded |
| AQT LRZ Ion-Trap System | LRZ | 20 | operational |
| PIAST-Q | PSNC | 20 | operational |
| IonQ Aria | IonQ | 25 | decommissioned |
| AQT IBEX Q1 | AQT | 12 | operational |
| IonQ Forte | IonQ | 36 | operational |