We investigate entanglement detection when the local measurements only nearly correspond to those intended. This corresponds to a scenario in which measurement devices are not perfectly controlled, but nevertheless operate with bounded inaccuracy. We formalize this through an operational notion of inaccuracy that can be estimated directly in the lab. To demonstrate the relevance of this approach, we show that small magnitudes of inaccuracy can significantly compromise several well-known entanglement witnesses. For two arbitrary-dimensional systems, we show how to compute tight corrections to a family of standard entanglement witnesses due to any given level of measurement inaccuracy. We also develop semidefinite programming methods to bound correlations in these scenarios.

中文翻译：

---

不精确测量的纠缠检测

当局部测量值几乎与预期相符时，我们研究纠缠检测。这对应于测量设备没有得到完美控制，但仍以有限的不准确度运行的情况。我们通过可以在实验室直接估计的不准确性的操作概念来正式化这一点。为了证明这种方法的相关性，我们表明，小幅度的不准确性会严重损害几个著名的纠缠证人。对于两个任意维系统，我们展示了如何计算由于任何给定级别的测量不准确而导致的标准纠缠证人系列的严格校正。我们还开发了半定编程方法来绑定这些场景中的相关性。