论文标题
单个量子系统的自我测试：理论和实验
Self-Testing of a Single Quantum System: Theory and Experiment
论文作者
论文摘要
用最少的假设认证单个量子设备对于开发量子技术至关重要。在这里，我们研究了如何利用单个系统的情境来实现自我测试。我们基于最简单的上下文量子系统，Klyachko-Can-binicioğlu-Shumovsky（KCBS）不平等的最简单上下文量子系统的最简单上下文见证，开发了强大的自我测试协议。我们在状态的忠诚度和测量值（理想配置）上建立了一个下限，这是证人在务实假设下的价值的函数，这是我们称为KCBS正交性条件的测量值。我们在实验中应用该方法，并在单个被困的$^{40} {\ rm ca}^+$和接近完美的检测效率上进行随机选择的测量。观察到的统计数据使我们能够进行自我测试，并提供单个系统量子自测的第一个实验证明。此外，我们量化并报告说，与我们的假设的偏差很小，这是情境实验以前忽略的一个方面。
Certifying individual quantum devices with minimal assumptions is crucial for the development of quantum technologies. Here, we investigate how to leverage single-system contextuality to realize self-testing. We develop a robust self-testing protocol based on the simplest contextuality witness for the simplest contextual quantum system, the Klyachko-Can-Binicioğlu-Shumovsky (KCBS) inequality for the qutrit. We establish a lower bound on the fidelity of the state and the measurements (to an ideal configuration) as a function of the value of the witness under a pragmatic assumption on the measurements we call the KCBS orthogonality condition. We apply the method in an experiment with randomly chosen measurements on a single trapped $^{40}{\rm Ca}^+$ and near-perfect detection efficiency. The observed statistics allow us to self-test the system and provide the first experimental demonstration of quantum self-testing of a single system. Further, we quantify and report that deviations from our assumptions are minimal, an aspect previously overlooked by contextuality experiments.
