Resilience of orbital angular momentum qubits and effects on hybrid entanglement

TL;DR

This paper investigates how physical obstructions impact the fidelity and entanglement of orbital angular momentum qubits, revealing their resilience and implications for quantum information processing.

Contribution

It provides a detailed analysis of how transverse obstructions affect OAM qubit fidelity and hybrid entanglement, advancing understanding of their robustness in practical scenarios.

Findings

Transverse obstructions reduce state fidelity of OAM qubits.

Planar and radial apertures differently affect entanglement.

OAM qubits show resilience under certain obstruction conditions.

Abstract

The orbital angular momentum of light (OAM) provides a promising approach for the implementation of multidimensional states (qudits) for quantum information purposes. In order to characterize the degradation undergone by the information content of qubits encoded in a bidimensional subspace of the orbital angular momentum degree of freedom of photons, we study how the state fidelity is affected by a transverse obstruction placed along the propagation direction of the light beam. Emphasis is placed on the effects of planar and radial hard-edged aperture functions on the state fidelity of Laguerre-Gaussian transverse modes and the entanglement properties of polarization-OAM hybrid-entangled photon pairs.