The idea behind the feat, first proposed in 1998, is to put a quantum computer into a “superposition”, a state in which it is both running and not running. It is as if you asked Schrödinger's cat to hit "Run".
With the right set-up, the theory suggested, the computer would sometimes get an answer out of the computer even though the program did not run.
"It is very bizarre that you know your computer has not run but you also know what the answer is," says team member Onur Hosten.
This scheme could have an advantage over straightforward quantum computing. "A non-running computer produces fewer errors," says Hosten.
You can't argue with that!