Abstract Quantum discord is a measure based on local projective measurements which captures quantum correlations that may not be fully captured by entanglement. A change in the measurement process, achieved by replacing rank-one projectors with a weak positive operator-valued measure (POVM), allows one to define weak variants of quantum discord. In this work, we experimentally simulate the effect of a weak POVM on a nuclear magnetic resonance quantum information processor. The two-qubit system under investigation is part of a three-qubit system, where one of the qubits is used as an ancillary to implement the phase damping channel. The strength of the weak POVM is controlled by varying the strength of the phase damping channel. We experimentally observed two weak variants of quantum discord namely, super quantum discord and weak quantum discord, in two-qubit Werner and Bell-diagonal states. The resultant dynamics of the states is investigated as a function of the measurement strength.

中文翻译：

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通过相位阻尼通道模拟弱测量的影响并确定核磁共振中二分相关的不同测量

摘要 量子不和谐是一种基于局部投影测量的测量方法，它捕获了纠缠可能无法完全捕获的量子相关性。通过用弱正算子值度量 (POVM) 替换排名第一的投影仪来实现测量过程的改变，允许定义量子不和谐的弱变体。在这项工作中，我们通过实验模拟了弱 POVM 对核磁共振量子信息处理器的影响。正在研究的两量子位系统是三量子位系统的一部分，其中一个量子位用作实现相位阻尼通道的辅助设备。弱 POVM 的强度是通过改变相位阻尼通道的强度来控制的。我们通过实验观察到量子不和谐的两种弱变体，即超量子不和谐和弱量子不和谐，在两个量子比特维尔纳和贝尔对角线状态。作为测量强度的函数研究状态的合成动态。