Delayed choice of paths selected by grin and snarl of quantum Cheshire Cat

TL;DR

This paper explores the quantum Cheshire Cat phenomenon, demonstrating how polarization components of a photon can be separated and their paths delayed or reversed before interaction, using a Mach-Zehnder interferometer setup.

Contribution

It introduces a method to control the path choice of photon polarization components in a delayed manner within a quantum interferometer.

Findings

Polarization components can be separated and manipulated independently.

Reversal of polarization component paths occurs before interaction with tuners.

Delayed choice effects are demonstrated in a quantum Cheshire Cat setup.

Abstract

The so-called quantum Cheshire Cat is a scenario where a photon, identified with a cat, and a component of its polarization, identified with the grin of that cat, are separated. We observe that the same techniques can be used to separate two orthogonal components of polarization of a photon, on an average. We identify these polarization components of the photon as the grin and snarl of the cat for ease of comprehension. A gedanken experiment is presented in which we simultaneously tune the input polarizations of the photon in the two arms of a Mach-Zehnder interferometer. It is noted that for two particular choices of photon polarization, the presence of the two components gets reversed in the two arms. This reversal of the grin and the snarl occurs before the polarization components even interact with the tuners, i.e., before the choice of which arm each should be in is made.