Quantitative wave-particle duality as quantum state discrimination

Abstract

We consider the problem of quantitative wave-particle duality from the perspective of quantum state discrimination. Specifically, we obtain quantifiers of both the particle aspect and the wave aspect from state discrimination. We show that the familiar one-bet duality relation coincides with the relation obtained from considerations of ambiguous discrimination, and the quantifiers suggested by unambiguous discrimination provide us with additional duality relations. In contrast to earlier similar works, the path asymmetry of the interferometer provides the ensemble to be discriminated, and therefore there is no need to introduce which-path detectors.