A Month On, the Million-Qubit Machine Settles Into Ordinary Work

SINGAPORE — The million-qubit processor the Singapore Institute demonstrated over the Q-Net backbone in mid-September has spent the weeks since not making headlines but making itself useful, running the tedious materials-simulation and logistics-optimization jobs that separate a stunt from an instrument. "The demonstration was the easy part," said Dr. Wei-Lin Tan, the quantum physicist who narrated the September run, standing beside a cryostat humming in a lab kept colder than deep space. "The hard part is the boring part — a machine that still works on a wet Tuesday when nobody is watching." Tan was careful, as she has been all year, to correct a persistent misreading: the Q-Net that carries the machine's traffic secures the channel with quantum keys, but does not transmit anything faster than light. "It makes the line unbreakable, not instant," she said. The processor now serves a rotating queue of academic and industrial users; its first month of ordinary uptime, Tan said, is the number she is proudest of.