Feasible quantum engineering of quantum multiphoton superpositions

TL;DR

This paper proposes a feasible experimental method for quantum non-Gaussian filtering of two-mode states, considering realistic detection inefficiencies, with potential applications in quantum metrology and communication.

Contribution

It introduces a practical quantum filtering scheme that accounts for detection inefficiencies, providing explicit operators for experimental implementation.

Findings

Explicit operator description of the filters under realistic conditions

Analysis of two models of detection inefficiency

Potential applications in quantum metrology and communication

Abstract

We examine an experimental setup implementing a family of quantum non-Gaussian filters. The filters can be applied to an arbitrary two-mode input state. We assume realistic photodetection in the filtering process and explore two different models of inefficient detection: a beam splitter of a small reflectivity located in front of a perfect detector and a Weierstrass transform applied to the unperturbed measurement outcomes. We explicitly give an operator which describes the coherent action of the filters in the realistic experimental conditions. The filtered states may find applications in quantum metrology, quantum communication and other quantum tasks.