Anomalous non-classicality via correlative and entropic Bell inequalities

Locality and Classicality: role of entropic inequalities

The use of the so-called entropic inequalities is revisited in the light of new quantum correlation measures, specially nonlocality. We introduce the concept of {\it classicality} as the non-violation of these classical inequalities by quantum states of several multiqubit systems and compare it with the non-violation of Bell inequalities, that is, {\it locality}. We explore --numerically and analytically-- the relationship between several other quantum measures and discover the deep connection existing between them. The results are surprising due to the fact that these measures are very differ…

On the insufficiency of entropic inequalities for detecting non-classicality in the Bell causal structure

Classical and quantum physics impose different constraints on the joint probability distributions of observed variables in a causal structure. These differences mean that certain correlations can be certified as non-classical, which has both foundational and practical importance. Rather than working with the probability distribution itself, it can instead be convenient to work with the entropies of the observed variables. In the Bell causal structure with two inputs and outputs per party, a technique that uses entropic inequalities is known that can always identify non-classical correlations. …

相对论中 Unruh-Dewitt 探测器的熵不确定性与量子非经典性

Entropic uncertainty and quantum non-classicality of Unruh-Dewitt detectors in relativity

本文研究相对论背景下 Unruh 热效应对一对 Unruh-Dewitt 探测器熵不确定性与量子 discord 的影响，发现加速会导致量子性损失和不确定性增大，且二者呈反向关联。

广义熵不确定性关系与Schwarzschild黑洞中的非经典性

Generalized entropic uncertainty relation and non-classicality in Schwarzschild black hole

本研究提出广义熵不确定性关系，揭示了Schwarzschild黑洞中量子相干性与纠缠的等价性，并展示了霍金温度对量子相干性的影响。

Information-theoretic Bell inequalities based on Tsallis entropy

We numerically investigate entropic Bell inequalities for a pair of entangled qutrits using information-theoretic distances. We show that for this class of inequalities Tsallis entropy is more suitable than Shannon as it reveals non-classicality for a larger set of quantum states. Finally, we find that like probability based inequalities, entropic ones are maximally violated by the non-maximally entangled qutrit state.

Single- and two-mode quantumness at a beam splitter

In the context of bipartite bosonic systems, two notions of classicality of correlations can be defined: P-classicality, based on the properties of the Glauber-Sudarshan P-function; and C-classicality, based on the entropic quantum discord. It has been shown that these two notions are maximally inequivalent in a static (metric) sense -- as they coincide only on a set of states of zero measure. We extend and reinforce quantitatively this inequivalence by addressing the dynamical relation between these types of non-classicality in a paradigmatic quantum-optical setting: the linear mixing at a be…