Discrimination of Optical Coherent States using a Photon Number Resolving Detector

TL;DR

This paper proposes a probabilistic quantum measurement strategy using a photon number resolving detector to discriminate two coherent states with lower error probabilities than traditional methods.

Contribution

It introduces a novel postselection-based measurement approach that improves discrimination accuracy for non-orthogonal quantum states.

Findings

Reduced error probability in state discrimination

Effective use of photon number resolving detectors

Comparison showing improvement over existing measurement strategies

Abstract

The discrimination of non-orthogonal quantum states with reduced or without errors is a fundamental task in quantum measurement theory. In this work, we investigate a quantum measurement strategy capable of discriminating two coherent states probabilistically with significantly smaller error probabilities than can be obtained using non-probabilistic state discrimination. We find that appropriate postselection of the measurement data of a photon number resolving detector can be used to discriminate two coherent states with small error probability. We compare our new receiver to an optimal intermediate measurement between minimum error discrimination and unambiguous state discrimination.