A quantum computer that measures light has achieved quantum supremacy

Lasers are used in a new type of quantum computing called boson sampling


A new type of quantum computing called boson sampling is capable of calculations that no classical computer could accomplish in any reasonable amount of time. This is the second time a quantum algorithm has claimed to achieve this feat, known as quantum supremacy, after Google made a claim of quantum supremacy using its Sycamore device in 2019.

Boson sampling relies on a strange quantum property of photons – particles of light – that is displayed when they travel through a beam splitter, which splits a single beam of light into two beams propagating in different directions. If two identical photons hit the beam splitter at exactly the same time, they will not split from one another, instead they stick together and both travel in the same direction.

If you shoot many photons through

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Light-based quantum computer Jiuzhang achieves quantum supremacy

A new type of quantum computer has proven that it can reign supreme, too.

A photonic quantum computer, which harnesses particles of light, or photons, performed a calculation that’s impossible for a conventional computer, researchers in China report online December 3 in Science. That milestone, known as quantum supremacy, has been met only once before, in 2019 by Google’s quantum computer (SN: 10/23/19). Google’s computer, however, is based on superconducting materials, not photons.

“This is the first independent confirmation of Google’s claim that you really can achieve quantum supremacy,” says theoretical computer scientist Scott Aaronson of the University of Texas at Austin. “That’s exciting.”

Named Jiuzhang after an ancient Chinese mathematical text, the new quantum computer can perform a calculation in 200 seconds that would take more than half a billion years on the world’s fastest non-quantum, or classical, computer.

“My first impression was, ‘wow,’” says quantum

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