双量子比特量子系统的时间不等式认证
Certification of two-qubit quantum systems with temporal inequality
AI总结：
针对现有双量子比特系统认证方案需兼容性条件的问题，提出基于时间不等式最大违背序列关联的自测试协议，无需子系统空间分离与兼容性条件，且对实验误差鲁棒，可有效认证目标态与测量。
AI中文摘要：
基于观测测量统计的量子器件自测试是一种用最少资源认证量子系统的方法。在参考文献[Phys. Rev. A 101, 032106 (2020)]中，一种基于观测展示Kochen-Specker语境性的测量统计的方案被证明可认证双量子比特纠缠态和测量，且无需子系统间的空间分离。但该方案假设了一组对测量的兼容性条件，这些条件对展示Kochen-Specker语境性至关重要。本工作中，我们提出一种自测试协议，无需兼容性条件假设即可认证上述双量子比特态和测量，同时也无需子系统间的空间分离。我们的协议基于观测导致时间不等式最大违背的序列关联，该时间不等式源自非语境性不等式。此外，我们的协议对小的实验误差或噪声具有鲁棒性。
英文摘要：
Self-testing of quantum devices based on observed measurement statistics is a method to certify quantum systems using minimal resources. In Ref. [Phys. Rev. \textbf{A} 101, 032106 (2020)], a scheme based on observing measurement statistics that demonstrate Kochen-Specker contextuality has been shown to certify two-qubit entangled states and measurements without the requirement of spatial separation between the subsystems. However, this scheme assumes a set of compatibility conditions on the measurements which are crucial to demonstrating Kochen-Specker contextuality. In this work, we propose a self-testing protocol to certify the above two-qubit states and measurements without the assumption of the compatibility conditions, and at the same time without requiring the spatial separation between the subsystems. Our protocol is based on the observation of sequential correlations leading to the maximal violation of a temporal inequality derived from non-contextuality inequality. Moreover, our protocol is robust to small experimental errors or noise.
