Quantum computers could in principle solve some complex mathematical problems that would take far too long on a regular, classical computer. However, efforts to make them practical and easily scalable have been stymied by the inherent instability of quantum states. Researchers in Japan recently developed an optical quantum computer that can be used for a variety of applications, a feature they say makes it the first general-purpose optical quantum computer in the world. While purpose-built optical quantum machines have been available for years, a general-purpose one has long been a goal of the industry. “The previous optical quantum computers are purpose-specific devices, such as a boson sampling machine and small-scale quantum computers with around 10 qubits,” says Hidehiro Yonezawa, team leader of the optical quantum control research team at the Riken Center for Quantum Computing. “Our quantum computer is a flexibly programmable quantum computer with a hundred analog quantum inputs.”

Full story : First Multiuse Optical Quantum Computer Comes to Japan.