Quantum Throughput: Quantifying quantum communication with homodyne measurements

TL;DR

This paper introduces a method to quantitatively assess the quantum throughput of optical communication devices using homodyne measurements, extending previous minimal-resource verification techniques.

Contribution

It develops a new approach for quantifying quantum correlations in optical devices through homodyne measurements, advancing beyond previous minimal-resource verification methods.

Findings

Demonstrates the method with input coherent states and homodyne detection

Provides a quantitative measure of quantum throughput in optical devices

Extends minimal-resource verification to a quantitative regime

Abstract

Quantum communication relies on optical implementations of channels, memories and repeaters. In the absence of perfect devices, a minimum requirement on real-world devices is that they preserve quantum correlations, meaning that they have some thoughput of a quantum mechanical nature. Previous work has verified throughput in optical devices while using minimal resources. We extend this approach to the quantitative regime. Our method is illustrated in a setting where the input consists of two coherent states while the output is measured by two homodyne measurement settings.