From the BBC:
Researchers have devised a penny-sized silicon chip that uses photons to run Shor's algorithm - a well-known quantum approach - to solve a maths problem.
The algorithm computes the two numbers that multiply together to form a given figure, and has until now required laboratory-sized optical computers.
This kind of factoring is the basis for a wide variety of encryption schemes.
The work, reported in Science, is rudimentary but could easily be scaled up to handle more complex computing.
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