A Hybrid Long-Distance Entanglement Distribution Protocol

TL;DR

This paper introduces a hybrid quantum repeater protocol that uses continuous and discrete variables, enabling long-distance entanglement distribution with near-deterministic swapping using linear optics and homodyne detection.

Contribution

It presents a novel hybrid protocol combining continuous and discrete variables for quantum repeaters, utilizing Schrödinger cat states and linear optics for efficient entanglement swapping.

Findings

Near-deterministic entanglement swapping with Schrödinger cat states

Efficient entanglement distribution over long distances

Performance evaluation of the hybrid protocol

Abstract

We propose a hybrid (continuous-discrete variable) quantum repeater protocol for distribution of entanglement over long distances. Starting from entangled states created by means of single-photon detection, we show how entangled coherent state superpositions, also known as `Schr\"odinger cat states', can be generated by means of homodyne detection of light. We show that near-deterministic entanglement swapping with such states is possible using only linear optics and homodyne detectors, and we evaluate the performance of our protocol combining these elements.