Comment on "Non-monotonic projection probabilities as a function of distinguishability"

TL;DR

This paper critiques a previous claim by demonstrating that observed nonmonotonic behaviors in quantum systems do not necessarily indicate a quantum-to-classical transition, emphasizing the importance of proper interpretation.

Contribution

The authors clarify that nonmonotonic structures are not exclusive indicators of quantum-to-classical transition, challenging prior interpretations and clarifying the phenomena's scope.

Findings

Nonmonotonic structures are present in single-photon and semi-classical systems.

Such structures do not necessarily signify a quantum-to-classical transition.

Previous claims linking these structures to quantum-classical transition are unsustainable.

Abstract

A recent work (2014 New J. Phys. 16 013006) claims that nonmonotonic structures found in the many-particle quantum-to-classical transition (2013 Proc. Natl Acad. Sci. USA 110 1227-1231; 2011 Phys. Rev. A 83 062111) are not exclusive to the many-body domain, but they also appear for single-photon as well as for semi-classical systems. We show that these situations, however, do not incorporate any quantum-to-classical transition, which makes the claims unsustainable.