Experimental demonstration of continuous variable purification of squeezed states

TL;DR

This paper demonstrates experimentally that linear optical devices can purify nonclassical continuous variable states, improving their squeezing and reducing decoherence in optical channels.

Contribution

It provides the first experimental validation of a purification protocol for nonclassical continuous variable states using linear optics.

Findings

Purification improves the degree of squeezing in nonclassical states.

The protocol reduces decoherence effects in optical transmission.

Linear optical devices are effective for state purification.

Abstract

We report on the first experimental demonstration of purification of nonclassical continuous variable states. The protocol uses two copies of phase-diffused states overlapped on a beam splitter and provides Gaussified, less mixed states with the degree of squeezing improved. The protocol uses only linear optical devices such as beam splitters and homodyne detection, thereby proving these optical elements can be used for successful purification of this type of state decoherence which occurs in optical transmission channels.