Testing Born’s rule via photoionization of helium

Abstract State-of-the-art attosecond photoionization experiments are identified as a new platform to test Born’s rule—a postulate of quantum mechanics. A simulation of the so-called Sorkin test under typical experimental conditions infers an achievable measurement precision in the range of the best Sorkin tests to date, demonstrating new opportunities for high-precision tests of Born’s rule via nonlinear matter-wave interferometry. The potential of attosecond photoionization for further fundamental tests of quantum mechanics is discussed.