The 20-qubit quantum computer has been integrated into the world's sixth-fastest supercomputer, Fugaku.
Riken
Engineers in Japan have activated Reimei, the world’s first hybrid quantum supercomputer. The 20-qubit quantum machine has been integrated into Fugaku, the world’s sixth-fastest supercomputer.
The hybrid system is designed to solve problems that classical supercomputers take much longer to process. The machine is housed at the Riken scientific institute in Saitama, near Tokyo, and will primarily support research in physics and chemistry.
Representatives from Quantinuum, the makers of Reimei, and Riken stated that integrating quantum computing with Fugaku is a major step forward in high-performance computing. Quantum computers have the potential to complete calculations in minutes or seconds that would take classical computers millions of years.
However, until quantum computers become more reliable and scalable, scientists believe hybrid systems like Reimei-Fugaku can serve as an effective solution.
Trapped-ion qubits for greater precision
Reimei is different from most quantum computers, which rely on superconducting qubits. Instead, it uses trapped-ion qubits, a technology that offers several advantages in stability and control.
This method involves isolating charged atoms, or ions, within an electromagnetic field, creating what is known as an ion trap. The trapped ions are then manipulated using precisely calibrated lasers, which adjust their quantum states to perform computations.
This technology allows scientists to manipulate ions so they can act as qubits, storing and processing quantum information. Trapped-ion qubits provide longer coherence times and encourage more connections between qubits. In contrast, superconducting qubits offer faster gate connections and are easier to fabricate on chips.
Riken representatives explained that Quantinuum’s unique architecture was a key reason for choosing its quantum system. Reimei uses a process called “ion shuttling,” which physically moves qubits around a circuit as needed. This allows for more complex algorithms and improved quantum processing.
Advanced error correction for stable computation
One of the biggest challenges in quantum computing is qubit errors. Quantum bits are highly sensitive to disturbances, leading to “noise” that affects calculations. To improve accuracy, Reimei groups multiple physical ion qubits into “logical qubits,” which store the same information in several places.
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Logical qubits help reduce errors by spreading out potential failure points. This means a single qubit failure does not disrupt an ongoing calculation. Quantinuum had previously achieved a breakthrough by creating a logical qubit with an error rate 800 times lower than physical qubits.
Reimei-Fugaku is the first fully operational hybrid quantum supercomputer. Other companies have tested similar systems, such as IQM’s 20-qubit quantum processor integrated into Germany’s SuperMUC-NG in June 2024.
However, that system remains in the testing phase, with no confirmed public launch date. IQM plans to integrate a 54-qubit system in 2025 and a 150-qubit chip in 2026.
With Reimei now operational, Japan has taken the lead in quantum-supercomputer integration, paving the way for more advanced computing solutions in the future.