Retrieving the Covariance Matrix of an Unknown Two-Mode Gaussian State by Means of a Reference Twin Beam

TL;DR

This paper presents a method to determine the covariance matrix of an unknown two-mode Gaussian state by interfering it with a known reference twin beam and analyzing correlation intensity moments.

Contribution

The paper introduces a novel technique using reference twin beams and phase variation to reconstruct the covariance matrix of unknown Gaussian states.

Findings

Successfully reconstructs covariance matrices using the proposed interference method.

Demonstrates the effectiveness of phase variation in extracting correlation moments.

Provides a practical approach for quantum state characterization.

Abstract

A method for revealing the covariance matrix of an unknown two-mode Gaussian state is given based on the interference with a reference twin beam whose covariance matrix is known. In the method, first- and second-order cross-correlation intensity moments are determined varying the overall phase of the reference twin beam.