Designing a compact cavity-enhanced source of entangled photons

TL;DR

This paper introduces a novel cavity-enhanced entangled photon source design using two nonlinear crystals within a single cavity, optimized for quantum network applications requiring efficient photon coupling and compatibility with quantum memories.

Contribution

The paper presents a new cavity design with two nonlinear crystals inside a single cavity, balancing complexity, photon bandwidth, and entanglement quality for quantum networks.

Findings

Design achieves compatibility with quantum memories

Balances cavity complexity with photon bandwidth

Enhances entanglement quality for quantum communication

Abstract

Entanglement will be the key resource of future large-scale quantum networks, enabling quantum communication and advanced quantum applications like distributed quantum sensing and distributed quantum computing. To this end, entanglement will have to be distributed over large distances and efficiently coupled to quantum devices at the network nodes. This requires the entangled photons to have wavelengths and bandwidths compatible with the quantum memories in quantum repeater nodes or quantum devices at client nodes. Here, we present a novel cavity-enhanced source design using two nonlinear crystals inside a single cavity. We provide detailed considerations balancing the complexity of the cavity design with the photon bandwidth and the entanglement quality.