Quantum Entanglement of High Angular Momenta

TL;DR

This paper demonstrates the generation of entangled photons with extremely high orbital angular momentum differences, up to 600 quanta, and explores their potential to enhance angular resolution in remote sensing.

Contribution

It introduces a method to transfer polarization entanglement to high OAM states and verifies entanglement at unprecedented quantum numbers, pushing the limits of quantum entanglement in orbital angular momentum.

Findings

Entanglement verified up to 600 quanta difference in OAM.

High OAM entanglement can improve angular resolution in remote sensing.

Technical limitations currently restrict the maximum achievable OAM quantum number.

Abstract

Single photons with helical phase structures may carry a quantized amount of orbital angular momentum (OAM) and their entanglement is important for quantum information science and fundamental tests of quantum theory. Because there is no theoretical upper limit on how many quanta of OAM a single photon can carry, it is possible to create entanglement between two particles with an arbitrary high difference in the quantum number. By transferring polarization entanglement to OAM with an interferometric scheme, we generate and verify entanglement up to 600 quanta difference in the orbital angular momentum. The only restrictive factors towards higher numbers are current technical limitations. We also experimentally demonstrate that the entanglement of very high OAM can improve the sensitivity of the angular resolution in remote sensing.