Contextuality, Coherences, and Quantum Cheshire Cats

Jonte R. Hance, Ming Ji, Holger Friedrich Hofmann

We analyse the quantum Cheshire cat using contextuality theory. The results shed a surprising new light on the relation between quantum paradoxes, weak values, and contextuality, a key resource for quantum computing.

Allen Stairs, Jeffrey Bub

Jonte R. Hance, Ming Ji, Holger Friedrich Hofmann

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 post-selected systems.

Zhenghao Liu

Ángel S. Sanz, F. Borondo

Zhenghao Liu