The article discusses the distinction between quantum entanglement and classical non-separability. It highlights that non-separability is a mathematical property that is independent of the physical nature of the different degrees of freedom, whereas the ability to perform measurements depends on the physical nature of the degree of freedom.
The authors identify four defining properties that lead to non-separable states of principally different physical nature: (1) systems with two distinct objects, (2) non-local systems, (3) systems allowing for two distinct measurements, and (4) systems that are mathematically non-separable.
The article provides examples of these different types of non-separable states, emphasizing the role of measurement in assessing the quantum nature of correlations. Quantum entanglement involves statistical correlations between the outcomes of two projective measurements on two partitions of the Hilbert space. In contrast, classical non-separability typically refers to deterministic correlations between a single measurement and a unitary filter or sorter operation.
The authors also discuss the concepts of locality and non-locality, clarifying that the violation of local realism is not about locality per se, but rather about the violation of the principle of reality. Quantum mechanics is local, but the assumption of realism is incorrect.
Overall, the article provides a clear operational distinction between quantum entanglement and classical non-separability, highlighting the crucial role of measurement in assessing the quantum nature of correlations.
Na inny język
z treści źródłowej
arxiv.org
Głębsze pytania