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arXiv:quant-ph/0005119

Separability of Density Matrices and Conditional Information Transmission

Robert R. Tucci

Published May 28, 2000• 14 citations
arXivHTMLPDF

Abstract

We give necessary and sufficient conditions under which a density matrix acting on a two-fold tensor product space is separable. Our conditions are given in terms of quantum conditional information transmission.
DOI
10.48550/arxiv.quant-ph/0005119

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Separability of Rank-Two Quantum States in CM⊗CNC^M \otimes C^NCM⊗CN Composite Quantum Systems
The state that an observer attributes to a quantum system depends on the information available to that observer. If two or more observers have different information about a single system, they will in general assign different states. Is there any restriction on what states can be assigned, given reasonable assumptions about how the observers use their information? We derive necessary and sufficient conditions for a group of general density matrices to characterize what different people may know about one and the same physical system. These conditions are summarized by a single criterion, which we term compatibility.