Generating superposition of up-to three photons for continuous variable quantum information processing

TL;DR

This paper presents an experimental method using a continuous-wave laser to generate arbitrary superpositions of up to three photons, enabling advanced quantum information processing with observable nonclassical states.

Contribution

The authors demonstrate a novel cw laser-based scheme for creating photon superpositions up to three photons, compatible with quantum teleportation and measurement-based operations.

Findings

Successfully generated superpositions of 0 to 3 photons

Observed multiple negativity regions in Wigner functions

High detection efficiency confirmed nonclassical states

Abstract

We develop an experimental scheme based on a continuous-wave (cw) laser for generating arbitrary superpositions of photon number states. In this experiment, we successfully generate superposition states of zero to three photons, namely advanced versions of superpositions of two and three coherent states. They are fully compatible with developed quantum teleportation and measurement-based quantum operations with cw lasers. Due to achieved high detection efficiency, we observe, without any loss correction, multiple areas of negativity of Wigner function, which confirm strongly nonclassical nature of the generated states.