Scientific article
Open access

Size of quantum superpositions as measured with classical detectors

Publication date2014

We propose a criterion which defines whether a superposition of two photonic components is macroscopic. It is based on the ability to discriminate these components with a particular class of “classical” detectors, namely, a photon number measurement with a resolution coarse-grained by noise. We show how our criterion can be extended to a measure of the size of macroscopic superpositions by quantifying the amount of noise that can be tolerated and taking the distinctness of two Fock states differing by N photons as a reference. After applying our measure to several well-known examples, we demonstrate that the superpositions which meet our criterion are very sensitive to phase fluctuations. This suggests that quantifying the macroscopicity of a superposition state through the distinguishability of its components with “classical” detectors not only is a natural measure but also explains why it is difficult to observe superpositions at the macroscopic scale.

Citation (ISO format)
SEKATSKI, Pavel, SANGOUARD, Nicolas Bruno, GISIN, Nicolas. Size of quantum superpositions as measured with classical detectors. In: Physical review, A, Atomic, molecular, and optical physics, 2014, vol. 89, n° 1. doi: 10.1103/PhysRevA.89.012116
Main files (1)
Article (Published version)
ISSN of the journal1050-2947

Technical informations

Creation05/12/2014 2:19:00 PM
First validation05/12/2014 2:19:00 PM
Update time03/14/2023 9:13:02 PM
Status update03/14/2023 9:13:02 PM
Last indexation01/16/2024 9:58:56 AM
All rights reserved by Archive ouverte UNIGE and the University of GenevaunigeBlack