October 7, 2025 Researchers in Japan have built a quantum computer containing 6,000 qubits — the largest system ever created — and, for the first time, it operates at room temperature.
The team from Japan’s National Institute for Materials Science (NIMS) and the University of Tsukuba achieved the breakthrough using molecular magnets, tiny chemical structures that can maintain quantum coherence without supercooling. The result could make quantum computing cheaper and more practical by eliminating the need for the extreme refrigeration normally required to keep qubits stable.
Until now, the largest quantum system belonged to D-Wave Systems, a Canadian company whose Advantage2 quantum annealer contains about 5,760 qubits but must operate at near-absolute zero. IBM’s Condor processor, announced in 2023, runs with 1,121 qubits and also relies on cryogenic cooling.
The Japanese researchers say their molecular magnet design allows qubits to function at normal room temperatures while preserving coherence — the fragile state that lets quantum bits exist in multiple states at once. That stability is what makes quantum computers vastly more powerful than traditional ones for certain kinds of problems.
Experts caution that the system still needs to demonstrate useful computation, but the result challenges long-held assumptions that quantum computing must rely on cryogenic hardware. If scalable, it could shift the economics of the field, allowing larger and more accessible systems without costly cooling infrastructure.
