Violation of local realism in a high-dimensional two-photon setup with non-integer spiral phase plates

TL;DR

This paper introduces a novel high-dimensional two-photon experimental setup using non-integer spiral phase plates to test quantum non-locality, predicting a strong violation of Bell inequalities beyond qubit limits.

Contribution

It presents a new experimental configuration for high-dimensional quantum non-locality tests utilizing non-integer spiral phase plates with only two detectors.

Findings

Predicted violation of Bell inequality with S=16/5 for half-integer spiral phase plates.

Setup enables probing of high-dimensional orbital angular momentum states.

Demonstrates stronger non-local correlations than in two-qubit systems.

Abstract

We propose a novel setup to investigate the quantum non-locality of orbital angular momentum states living in a high-dimensional Hilbert space. We incorporate non-integer spiral phase plates in spatial analyzers, enabling us to use only two detectors. The resulting setup is somewhat reminiscent of that used to measure polarization entanglement. However, the two-photon states that are produced, are not confined to a 2X2-dimensional Hilbert space, and the setup allows the probing of correlations in a high-dimensional space. For the special case of half-integer spiral phase plates, we predict a violation of the Clauser-Horne-Shimony-Holt version of the Bell inequality (S<=2), that is even stronger than achievable for two qubits (S=2*(2^1/2)), namely S=16/5