Robust Measurement for the Discrimination of Binary Coherent States

TL;DR

This paper presents a robust, scalable measurement strategy using photon number resolving detection for discriminating binary coherent states, capable of surpassing the quantum noise limit in practical, high-rate quantum communication scenarios.

Contribution

It introduces an optimized single-shot measurement approach with PNR detection that is robust to noise and imperfections, enabling practical surpassing of the quantum noise limit.

Findings

Achieves high robustness to noise and imperfections.

Scalable to high communication rates.

Potential to surpass the quantum noise limit in realistic settings.

Abstract

The discrimination of two nonorthogonal states is a fundamental element for secure and efficient communication. Quantum measurements of nonorthogonal coherent states can enhance information transfer beyond the limits of conventional technologies. We demonstrate a strategy for binary state discrimination based on optimized single-shot measurements with photon number resolving (PNR) detection with finite number resolution. This strategy enables a high degree of robustness to noise and imperfections while being scalable to high rates and in principle allows for surpassing the quantum noise limit (QNL) in practical situations. These features make the strategy inherently compatible with high-bandwidth communication and quantum information applications, providing advantages over the QNL under realistic conditions.