Japanese national research institute RIKEN has procured and begun deploying Quantinuum‘s System Model H2 trapped-ion quantum computer, upgrading the “Reimei-Fugaku” hybrid computing facility. Installed on-site at RIKEN’s research campus near Tokyo, the 56-qubit system replaces its 20-qubit H1 predecessor to scale physical capacity, gate fidelity, and computational active space across Japan’s national supercomputing infrastructure.
| RIKEN Reimei Platform Hardware Upgrade Specifications | ||
|---|---|---|
| System Dimension | Baseline Configuration (H1 Architecture) | Upgraded Configuration (System Model H2) |
| Qubit Modality & Scale | 20 trapped-ion physical qubits | 56 trapped-ion physical qubits with all-to-all connectivity. |
| Core Architecture | Quantum Charge-Coupled Device (QCCD) | Linear-shuttling QCCD supporting arbitrary pair-wise entangling operations without compile-time SWAP overhead. |
| Supercomputing Backend | Supercomputer Fugaku (RIKEN R-CCS, Kobe) | Maintains direct-access API integration with Fugaku’s A64FX compute partitions to bypass cloud queue latency. |
| Commissioning Framework | NEDO National Project / METI | Operated under Japan’s JHPC-quantum hybrid compute initiative. |
| Primary Application Scope | 16-logical-qubit biomolecular active sites | Expanded active-space Hamiltonian modeling for drug discovery and materials science. |
The Reimei-Fugaku platform links Quantinuum’s on-premises ion trap directly to the Fugaku supercomputer, establishing an operational testbed to evaluate how classical high-performance computing clusters and quantum coprocessors exchange data under production workloads.
The transition to the 56-qubit H2 processor directly addresses the active-space constraints encountered in earlier demonstrations. In initial computational chemistry benchmarks, researchers simulated the strongly correlated active site of a retinal chromophore inside a carbon nanotube wall by sampling electronic configurations across 16 logical qubits on Reimei before diagonalizing the resulting subspace Hamiltonian on Fugaku. The upgraded QCCD hardware expands the configuration space that can be sampled natively, allowing users in the national JHPC-quantum program to target larger multiconfigurational molecular Hamiltonians and complex condensed-matter systems beyond classical brute-force limits.
Official details are in the Quantinuum Announcement here, with earlier workflow benchmarks covered in Quantinuum and RIKEN Execute End-to-End Hybrid Quantum-HPC Chemistry on Fugaku and Reimei here.
November 10, 2026