QuTech, Delft University of Technology, P.O. Box 5046, 2600 GA Delft, Netherlands.
Netherlands Organisation for Applied Scientific Research (TNO), P.O. Box 155, 2600 AD Delft, Netherlands.
Phys Rev Lett. 2019 Aug 9;123(6):063601. doi: 10.1103/PhysRevLett.123.063601.
We report on the realization and verification of quantum entanglement between a nitrogen-vacancy electron spin qubit and a telecom-band photonic qubit. First we generate entanglement between the spin qubit and a 637 nm photonic time-bin qubit, followed by photonic quantum frequency conversion that transfers the entanglement to a 1588 nm photon. We characterize the resulting state by correlation measurements in different bases and find a lower bound to the Bell state fidelity of ≥0.77±0.03. This result presents an important step towards extending quantum networks via optical fiber infrastructure.
我们报告了氮空位电子自旋量子位和电信波段光子量子位之间量子纠缠的实现和验证。首先，我们在自旋量子位和 637nm 光子时间-bin 量子位之间产生纠缠，然后进行光子量子频率转换，将纠缠转移到 1588nm 光子上。我们通过不同基下的相关测量来表征产生的态，并发现贝尔态保真度的下限为≥0.77±0.03。这一结果为通过光纤基础设施扩展量子网络迈出了重要一步。
