Witnessing non-classicality beyond quantum theory

Witnessing non-classicality beyond quantum theory. Published in Physical Review D. By Chiara Marletto (QISS Oxford Physics) and Vlatko Vedral (QISS Oxford Physics).

Popular Summary:
This paper provides the strongest theoretical basis for recently proposed experiments to test quantum effects in gravity, achieving the remarkable result that such experiments, if performed successfully, would rule out all plausible models of semi-classical gravity (those known and those yet to be discovered). Roughly speaking, semi-classical gravity is the idea that spacetime is not behaving as a quantum system. The paper is making use of radically new tools: it is based on general information-theoretic principles drawn from the recently proposed constructor theory, which is a generalisation of the quantum theory of computation beyond quantum theory.