Experimental demonstration of robustness of Gaussian quantum coherence

TL;DR

This paper experimentally demonstrates that Gaussian quantum coherence remains robust in noisy quantum channels, highlighting its potential as a resilient quantum resource distinct from entanglement and squeezing.

Contribution

The study provides the first experimental quantification of Gaussian quantum coherence in noisy channels, showing its robustness compared to other quantum properties.

Findings

Quantum coherence remains stable under loss and noise.

Gaussian EPR states retain coherence better than entanglement.

Results suggest potential for coherence-based quantum information in noisy environments.

Abstract

Besides quantum entanglement and steering, quantum coherence has also been identified as a useful quantum resource in quantum information. It is important to investigate the evolution of quantum coherence in practical quantum channels. In this paper, we experimentally quantify the quantum coherence of a squeezed state and a Gaussian Einstein-Podolsky-Rosen (EPR) entangled state transmitted in Gaussian thermal noise channel, respectively. By reconstructing the covariance matrix of the transmitted states, quantum coherence of these Gaussian states is quantified by calculating the relative entropy. We show that quantum coherence of the squeezed state and the Gaussian EPR entangled state is robust against loss and noise in a quantum channel, which is different from the properties of squeezing and Gaussian entanglement. Our experimental results pave the way for application of Gaussian quantum coherence in lossy and noisy environments.