Quasiprobability distributions with weak measurements
Abstract
We discuss and experimentally demonstrate the role of quantum coherence in a sequence of two measurements collected at different times using weak measurements. For this purpose, we have realized a weak-sequential measurement protocol with photonic qubits, where the first measurement is carried out as a positive operator-valued measure, whereas the second one is a projective operation. We determine the quasiprobability distributions associated to this procedure using both the commensurate and the Margenau-Hill quasiprobabilities approaches. By tuning the weak measurements, we obtain a quasidistribution that may or may not exhibit negative parts, depending on the suitability of a contextual model for describing the experiment. Our results show how quasidistributions may find application in inspecting quantum monitoring, when part of the initial quantum coherence needs to be preserved.
Cite
@article{arxiv.2406.06713,
title = {Quasiprobability distributions with weak measurements},
author = {Gabriele Bizzarri and Stefano Gherardini and Mylenne Manrique and Fabio Bruni and Ilaria Gianani and Marco Barbieri},
journal= {arXiv preprint arXiv:2406.06713},
year = {2025}
}
Comments
Revised version, close to the accepted one. 8 pages, 6 figures