Advanced Quantum Noise

TL;DR

This paper demonstrates the first advancement of a bright nonclassical light state using twin-beams in a medium with anomalous dispersion, revealing quantum correlation degradation near the quantum limit.

Contribution

It introduces a novel experimental setup employing four-wave mixing in rubidium vapor to advance nonclassical light while preserving quantum correlations.

Findings

Successful advancement of bright nonclassical twin-beams.

Quantum correlations degrade near the fundamental quantum limit.

First demonstration of nonclassical state advancement in anomalous dispersion media.

Abstract

We use the quantum correlations of twin-beams of light to probe the added noise when one of the beams propagates through a medium with anomalous dispersion. The experiment is based on two successive four-wave mixing processes in rubidium vapor, which allow for the generation of bright two-mode-squeezed twin-beams followed by a controlled advancement while maintaining the shared quantum-correlations between the beams. The demonstrated effect allows the study of irreversible decoherence in a medium exhibiting anomalous dispersion, and for the first time shows the advancement of a bright nonclassical state of light. The advancement and corresponding degradation of the quantum correlations are found to be operating near the fundamental quantum limit imposed by using a phase-insensitive amplifier.