Quantum illumination receiver using double homodyne detection

TL;DR

This paper proposes a linear optical quantum receiver using double homodyne detection for quantum illumination, achieving improved signal-to-noise ratio and noise robustness over simpler existing receivers.

Contribution

It introduces a realizable linear optical quantum receiver for Gaussian QI that avoids nonlinear effects, simplifying implementation while enhancing performance.

Findings

Better signal-to-noise ratio than existing receivers

More robust against noise in various regimes

Effective across different target reflectivities and noise levels

Abstract

A quantum receiver is an essential element of quantum illumination (QI) which outperforms its classical counterpart, called classical-illumination (CI). However, there are only few proposals for realizable quantum receiver, which exploits nonlinear effects leading to increasing the complexity of receiver setups. To compensate this, in this article, we design a quantum receiver with linear optical elements for Gaussian QI. Rather than exploiting nonlinear effect, our receiver consists of a 50:50 beam splitter and homodyne detection. Using double homodyne detection after the 50:50 beam splitter, we analyze the performance of the QI in different regimes of target reflectivity, source power, and noise level. We show that our receiver has better signal-to-noise ratio and more robust against noise than the existing simple-structured receivers.