Quantum supremacy, whereby a quantum computer solves a problem in a significantly shorter time than a conventional (classical) computer, may have been achieved for the first time.
Reaching this longstanding goal in physics and computer science is described in a draft paper that appears to be written by scientists at Google and the Quantum Artificial Intelligence Lab collaboration, which includes NASA researchers. The document appeared briefly on a NASA website before it was taken down. It is believed to be an early version of a paper that has been submitted to a leading scientific journal.
The paper describes how a quantum computer comprising 53 programmable superconducting quantum bits was used to determine the output of a randomly-chosen quantum circuit made from a sequence of quantum gates. The output is a string of binary numbers and if the process is repeated many times, the results can be described as a probability distribution that resembles an interference pattern. This arises from the quantum interference that underlies the operation of quantum circuit.
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