Entanglement-assisted scheme for nondemolition detection of the presence of a single photon

TL;DR

This paper introduces a resource-efficient linear-optical scheme for quantum nondemolition detection of single photons, enabling detection without disturbing the photon state and discussing tradeoffs and optimization strategies.

Contribution

It presents a novel, resource-optimal linear-optical method for nondemolition detection of single photons with tunable measurement and success probability.

Findings

Success probability of 1/2 for photon presence detection

Ability to perform nondemolition measurement of photon state

Discussion of resource optimality and success probability enhancement

Abstract

In this paper, we propose a resources-optimal linear-optical scheme for quantum nondemolition detection of single-photon presence. By measuring the state of ancillary photons, the presence of a photon in signal mode is revealed with a success probability of 1/2 without any disturbance to its state. We also show how to tune the setup to perform quantum nondemolition measurement of the signal photon state, and we provide tradeoff between the extracted information and the signal state disturbance. Moreover, the optimality of resources and methods by which to increase the success probability are discussed.