Contextuality, Coherences, and Quantum Cheshire Cats

TL;DR

This paper uses contextuality theory to analyze the quantum Cheshire cat paradox, revealing that the phenomenon is linked to quantum coherences and weak values rather than disembodiment of properties.

Contribution

It introduces a contextuality-based framework to interpret the quantum Cheshire cat, emphasizing the role of coherences and weak values in understanding the paradox.

Findings

The paradox can be explained through the relation between three measurement types.

Contextuality reveals the underlying quantum coherences involved.

The phenomenon reflects effects of coherences rather than property disembodiment.

Abstract

We analyse the quantum Cheshire cat using contextuality theory, to see if this can tell us anything about how best to interpret this paradox. We show that this scenario can be analysed using the relation between three different measurements, which seem to result in a logical contradiction. We discuss how this contextual behaviour links to weak values, and coherences between prohibited states. Rather than showing a property of the particle is disembodied, the quantum Cheshire cat instead demonstrates the effects of these coherences, which are typically found in pre- and postselected systems.