RIKEN Launches "A-II," Japan's New 144-Qubit Quantum Computer
- •RIKEN and Osaka University unveil the 'A-II' 144-qubit quantum computer.
- •The new machine doubles its predecessor's capacity, exceeding classical computer simulation limits.
- •A two-machine system ensures stable cloud operations for practical quantum research.
RIKEN and a research group from Osaka University have announced the launch of cloud services for "A-II," Japan's latest domestic quantum computer featuring 144 qubits. This represents a significant upgrade from the 64-qubit "A" launched in 2023, more than doubling its specifications and marking a critical turning point for the nation's quantum computing landscape. Since computing power increases exponentially with the number of qubits, a 144-qubit scale reaches a realm where full simulation by traditional classical computers—such as high-end PCs or supercomputers—is considered extremely difficult.
The key to this technical breakthrough lies in balancing hardware density with stability. The superconducting quantum chip, arranged in a 12x12 2D lattice, measures just 28mm square. Despite its compact size, researchers successfully extended the "qubit lifetime"—the duration information is retained—through efficient wiring and improved microwave control devices. Furthermore, the design emphasizes practicality, featuring reduced resonance frequencies to lower error rates during calculations. Remarkably, the entire apparatus, including advanced cooling systems, remains nearly as compact as its predecessor.
The operational benefits are equally significant for the research community. Previously, quantum computer services often had to be suspended for experiments or maintenance, but the establishment of a two-machine system comprising the original "A" and the new "A-II" now allows for more stable cloud delivery. Users can engage in research on complex algorithms within a hybrid environment that combines quantum and classical computing, integrating with RIKEN-provided simulators like "Qulacs" to advance their work.
The debut of "A-II" is not merely a race for higher specifications; it is a steady step toward the ambitious goal of achieving Fault-Tolerant Quantum Computing (FTQC), which can self-correct calculation errors. In the future, this domestic quantum technology is expected to lead the world as a foundation for developing new materials, optimizing complex logistics, and executing next-generation learning algorithms that push beyond the current limits of artificial intelligence.