Experimental verification of the Gaussian quantum correlation measure in continuous variable systems

The presence of quantum correlations in composite quantum systems is one of the main features of quantum mechanics. However, by now, all known quantifications of this correlation for continuous-variable systems are very difficult to compute. Therefore, it makes sense to find simpler and computable quantifications of Gaussian quantum correlations. Recently, a computable Gaussian quantum correlation M is proposed, which can be obtained based on the covariance matrix. Here, we experimentally demonstrate the Gaussian quantum correlation 𝑀 based on the two-mode entangled state carrying orbital angular momentum (OAM) generated from a four-wave mixing process in a hot Cesium atom vapor cell and investigate the evolution of such correlation in the lossy channel. Our results show that quantum correlation 𝑀 is robust in the lossy channel.