Whether the observables of a physical system admit real values is of fundamental importance to a deep understanding of nature. In this work, we report a device-independent experiment to confirm that the joint reality of two observables on a single two-level system is incompatible with the assumption of operational completeness, which is strictly weaker than that of preparation noncontextuality. We implement two observables on a trapped 171Yb+ ion to test this incompatibility via violation of certain inequalities derived from both linear and nonlinear criteria. Moreover, by introducing a highly controllable dephasing channel, we show that the nonlinear criterion is more robust against noise. Our results push the fundamental limit to delineate the quantum–classical boundary and pave the way for exploring relevant problems in other scenarios.

中文翻译：

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根据操作完整性实验性地排除联合现实

物理系统的可观测值是否承认真实值对于深入理解自然至关重要。在这项工作中，我们报告了一个与设备无关的实验，以确认单个两级系统上两个可观察量的联合现实与操作完整性的假设不相容，该假设严格弱于准备非上下文性的假设。我们在一个被困的对象上实现了两个可观察量 171镱+ 离子通过违反由线性和非线性标准导出的某些不等式来测试这种不兼容性。此外，通过引入高度可控的移相通道，我们表明非线性准则对噪声具有更强的鲁棒性。我们的结果突破了描绘量子经典边界的基本极限，并为探索其他场景中的相关问题铺平了道路。