Null weak values and the past of a quantum particle

Abstract

Non-destructive weak measurements (WM) made on a quantum particle allow to extract information as the particle evolves from a prepared state to a finally detected state. The physical meaning of this information has been open to debate, particularly in view of the apparent discontinuous trajectories of the particle recorded by WM. In this work we investigate the properties of vanishing weak values for projection operators as well as general observables. We then analyze the implications when inferring the past of a quantum particle. We provide a novel (non-optical) example for which apparent discontinuous trajectories are obtained by WM. Our approach is compared to previous results.

Minor changes; to be published in Phys Rev A

References in corpus (3)

• Knowing "where the photons have been"
• Measuring evolution of a photon in an interferometer with spectrally-resolved modes
• Asking photons where they have been in plain language

Cited by in corpus (3)

• Disembodiment of arbitrary number of properties in quantum Cheshire cat experiment
• Speakable and unspeakable in quantum measurements
• A minimalist's view of quantum mechanics