A model of a quantum measurement process is presented: a system consisting of a qubit in a superposition interacts with a measuring apparatus consisting of a $N$ qubit state. Looking at the emerging, effective description of the apparatus given by the action of a coarse-graining channel, we have been able to recover information about the superposition coefficients of the system. We have also been able to visualize the death of quantum correlations between system and apparatus and the death of quantum coherences in the apparatus' effective state, in the limit of a strong coarse-graining action—a situation akin to decoherence, although it is not necessary to evoke any interaction with the surrounding environment.

中文翻译：

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测量过程中量子衰减：粗粒度通道的作用

提出了一种量子测量过程的模型：一个由叠加的量子位组成的系统与一个由 $ñ$量子位状态。通过对粗粒度通道的作用给出的对设备的新兴有效描述，我们已经能够恢复有关系统叠加系数的信息。在强粗粒度作用的限制下，我们还能够可视化系统与设备之间的量子相关性的消亡以及设备有效状态下的量子相干性的消亡，这种情况类似于去相干，尽管并非如此唤起与周围环境的任何互动。