A little bit more than magic: the secret to quantum computing may lie in negativity

Researchers at the University of Cambridge have identified a stricter criterion for when quantum computers can outperform classical machines. Magic states, special qubit configurations required for universal quantum computation, are necessary but not always sufficient. Many states previously regarded as useful magic can still be simulated efficiently on classical computers. The team used the Kirkwood–Dirac distribution, a 1945 quasi-probability framework associated with Paul Dirac, to disting...