Simultaneous entanglement swapping of multiple orbital angular momentum states of light

TL;DR

This paper demonstrates the simultaneous entanglement swapping of multiple high-dimensional orbital angular momentum states of light, advancing quantum communication and foundational tests by handling thousands of spatial mode pairs at once.

Contribution

It introduces a degenerate filter enabling the simultaneous entanglement swapping of numerous orbital angular momentum states, significantly increasing the capacity of quantum networks.

Findings

Swapped entanglement across thousands of spatial light mode pairs.

Enhanced bandwidth for quantum communication.

Improved tests of quantum foundations with high-dimensional states.

Abstract

Entanglement swapping generates remote quantum correlations between particles that have not interacted and is the cornerstone of long-distance quantum communication, quantum networks, and fundamental tests of quantum science. In the context of spatial modes of light, high-dimensional entanglement provides an avenue to increase the bandwidth of quantum communications and provides more stringent limits for tests of quantum foundations. Here we simultaneously swap the entanglement of multiple orbital angular momentum states of light. The system is based on a degenerate filter that cannot distinguish between different anti-symmetric states, and thus entanglement swapping occurs for several thousand pairs of spatial light modes simultaneously.