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"Quantumness" versus "Classicality" of Quantum States

Berry Groisman·Dan Kenigsberg·Tal Mor
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Abstract

Entanglement is one of the pillars of quantum mechanics and quantum information processing, and as a result the quantumness of nonentangled states has typically been overlooked and unrecognized. We give a robust definition for the classicality versus quantumness of a single multipartite quantum state, a set of states, and a protocol using quantum states. We show a variety of nonentangled (separable) states that exhibit interesting quantum properties, and we explore the ``zoo'' of separable states; several interesting subclasses are defined based on their diagonalizing bases, and their non-classical behavior is investigated.

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Berry Groisman, Dan Kenigsberg, Tal Mor. 2007-03-13. "Quantumness" versus "Classicality" of Quantum States. https://arxiv.org/abs/quant-ph/0703103

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