Complete nonclassicality test with a photon-number resolving detector

TL;DR

This paper introduces a practical method for experimentally testing the nonclassicality of any quantum state using a photon-number resolving detector and coherent displacement, accounting for real-world imperfections.

Contribution

It proposes a complete nonclassicality test scheme that only requires simple optical components and photon-number resolving detection, enhancing experimental feasibility.

Findings

The method successfully tests nonclassicality in realistic scenarios.

Quantum efficiency and uncertainties are thoroughly analyzed.

Demonstrated with a realistic quantum state example.

Abstract

We present a method for the experimental measurement of nonclassicality witnesses and demonstrate its application. Our proposal only requires the coherent displacement of the initial state, which can be achieved by overlapping the latter with a coherent state at a beam splitter, and subsequent photon-number resolved detection. This setup allows a complete test of nonclassicality of an arbitrary quantum state. The role of the quantum efficiency as well as statistical and systematic uncertainties are discussed. Finally, the scheme is demonstrated for a realistic example.