EPR纠缠光束时域量子关联的实验验证

Experimental Testing of Time-domain Quantum Correlation of EPR Entangled Beams

我们利用平衡零拍探测系统和数据采集系统直接测量了EPR纠缠光束信号光场与闲置光场正交分量之间的时域量子起伏,验证了其量子关联。通过对EPR纠缠光束中的一束光场进行延迟,验证了信号光与闲置光不同步时将导致量子关联减弱乃至消失。我们的实验结果为开展连续变量量子密钥分发、非高斯态的实验制备和纠缠纯化奠定了实验基础。

We measured the quantum fluctuations of the quadratures of signal and idler beams of EPR entangled beams in time domain directly by using the bomodyne detection system and data acquisition system, and demonstrated intuitively the quantum correlations between two optical beams. By delaying one of the EPR entangled beams, we verify that if the measurements on the signal and the idler beams are not synchronal, the correlations between them will decrease and finally vanish. The presented experimental method can be utilized in developing quantum key distribution with continuous variables, experimental preparation of non-Gaussian state and entanglement purification.