CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, 230026, People's Republic of China.
CAS Center For Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, People's Republic of China.
Phys Rev Lett. 2019 Oct 25;123(17):170402. doi: 10.1103/PhysRevLett.123.170402.
In a measurement-device-independent or quantum-refereed protocol, a referee can verify whether two parties share entanglement or Einstein-Podolsky-Rosen (EPR) steering without the need to trust either of the parties or their devices. The need for trusting a party is substituted by a quantum channel between the referee and that party, through which the referee encodes the measurements to be performed on that party's subsystem in a set of nonorthogonal quantum states. In this Letter, an EPR-steering inequality is adapted as a quantum-refereed EPR-steering witness, and the trust-free experimental verification of higher dimensional quantum steering is reported via preparing a class of entangled photonic qutrits. Further, with two measurement settings, we extract 1.106±0.023 bits of private randomness per every photon pair from our observed data, which surpasses the one-bit limit for projective measurements performed on qubit systems. Our results advance research on quantum information processing tasks beyond qubits.
在一种无需信任任何一方或其设备的测量设备独立性或量子参考协议中，仲裁者可以验证双方是否共享纠缠或爱因斯坦-波多尔斯基-罗森（EPR）导引，而无需信任任何一方或其设备。通过仲裁者与该方之间的量子通道，可以替代对该方的信任，通过该通道，仲裁者可以在一组非正交量子态中对该方的子系统进行测量。在这封信中，适应了 EPR 导引不等式作为量子参考 EPR 导引见证，通过制备一类纠缠光子量子比特，报告了无需信任的更高维量子导引的实验验证。此外，通过两种测量设置，我们从观察到的数据中每对光子提取 1.106±0.023 比特的私有随机性，这超过了在量子比特系统上进行的投影测量的一位限制。我们的结果推进了超越量子比特的量子信息处理任务的研究。
