论文标题
通过量子随机访问代码的Unshap Qubit可观测值和顺序测量不兼容的实验表征
Experimental characterisation of unsharp qubit observables and sequential measurement incompatibility via quantum random access codes
论文作者
论文摘要
对于量子理论和量子信息应用中的基础见解，UNSHAR的测量越来越重要。在这里，我们报告了基于量子随机访问代码的顺序通信协议中UNSHARP量子测量值的实验实现。该协议涉及三方；第一方准备Qubit系统，第二方执行返回经典和量子结果的操作，后者由第三方衡量。我们演示了一个几乎最佳的顺序量子访问代码，该代码既优于最佳的经典协议，又超过了仅利用投影测量的任何量子协议。此外，虽然仅假设所涉及的设备在Qubits上操作并且检测到的事件构成了一个公平的样本，但我们证明了基于顺序量子随机访问代码的UNSHARP测量值的噪声表征。我们将此表征应用于量化两个顺序对量子测量对的不兼容程度。
Unsharp measurements are increasingly important for foundational insights in quantum theory and quantum information applications. Here, we report an experimental implementation of unsharp qubit measurements in a sequential communication protocol, based on a quantum random access code. The protocol involves three parties; the first party prepares a qubit system, the second party performs operations which return both a classical and quantum outcome, and the latter is measured by the third party. We demonstrate a nearly-optimal sequential quantum random access code that outperforms both the best possible classical protocol and any quantum protocol which utilises only projective measurements. Furthermore, while only assuming that the involved devices operate on qubits and that detected events constitute a fair sample, we demonstrate the noise-robust characterisation of unsharp measurements based on the sequential quantum random access code. We apply this characterisation towards quantifying the degree of incompatibility of two sequential pairs of quantum measurements.
