Ollivier Harold
Institut National de Recherche en Informatique et en Automatique, 2 Rue Simone Iff, 75012 Paris, France.
Entropy (Basel). 2022 Feb 14;24(2):277. doi: 10.3390/e24020277.
We examine the emergence of objectivity for quantum many-body systems in a setting without an environment to decohere the system's state, but where observers can only access small fragments of the whole system. We extend the result of Reidel (2017) to the case where the system is in a mixed state, measurements are performed through POVMs, and imprints of the outcomes are imperfect. We introduce a new condition on states and measurements to recover full classicality for any number of observers. We further show that evolutions of quantum many-body systems can be expected to yield states that satisfy this condition whenever the corresponding measurement outcomes are redundant.
我们在一种没有环境使系统状态退相干，但观察者只能访问整个系统的小片段的情形下，研究量子多体系统客观性的出现。我们将赖德尔（2017年）的结果扩展到系统处于混合态、测量通过正算子值测量（POVM）进行且结果印记不完美的情况。我们引入关于态和测量的一个新条件，以恢复任意数量观察者的完全经典性。我们进一步表明，只要相应的测量结果是冗余的，量子多体系统的演化就有望产生满足该条件的态。
