Experimental realization of entanglement in multiple degrees of freedom between two quantum memories
Wei Zhang, Dong-Sheng Ding, Ming‐Xin Dong, Shuai Shi, Kai Wang, Shi-Long Liu, Yan Li, Zhi‐Yuan Zhou, Bao‐Sen Shi, Guang‐Can Guo · Nature Communications · 2016
Entanglement in multiple degrees of freedom has many benefits over entanglement in a single one. The former enables quantum communication with higher channel capacity and more efficient quantum information processing and is compatible with diverse quantum networks. Establishing multi-degree-of-freedom entangled memories is not only vital for high-capacity quantum communication and computing, but also promising for enhanced violations of nonlocality in quantum systems. However, there have been yet no reports of the experimental realization of multi-degree-of-freedom entangled memories. Here we experimentally established hyper- and hybrid entanglement in multiple degrees of freedom, including path (K-vector) and orbital angular momentum, between two separated atomic ensembles by using quantum storage. The results are promising for achieving quantum communication and computing with many degrees of freedom.